SINKING SPRING, Pa. - For two years, the most visible struggle within Mark and Megan Short's family had been the angst, then joy, poured out in Facebook posts when their youngest daughter received a heart transplant at Children's Hospital of Philadelphia when she was only 6 days old.

Willow Short was, in the words of her mother, "one amazing little miracle who beat the odds!"

Now investigators, neighbors, and others are left trying to understand the more pernicious struggle - an unseen powder keg of apparent domestic conflict - that left the 2-year-old, once expected to die in the womb, dead alongside her brother, sister, and parents in their Berks County living room.

Authorities declined to say more Monday about the handwritten murder-suicide note they found, or which parent was closest to the gun. They ordered an autopsy of Mark Short.

But in interviews with some who knew them, a portrait began to emerge of the Shorts.

Before moving to this town just west of Reading, the pair had Philadelphia-area ties: He once lived in Folcroft, Delaware County. She was a graduate of Archbishop Ryan High School in Northeast Philadelphia. Her mother, a Bucks County newspaper editor, still lives there.

The couple worked in real estate, apparently doing well enough to settle on a leafy, hilly street where white-collar professionals enjoy 3,500-square-foot homes with swimming pools and swing sets.

Without elaborating, an affidavit of probable cause in the case cited "domestic issues." But friends of her mother's said Megan Short had been threatening to leave her husband - and had been spending recent weekends at her mother's house in Northeast Philadelphia. She reportedly planned to move to Yardley.

Instead, the family was making funeral arrangements for the 33-year-old mother, 2-year-old Willow, her 8-year-old sister Lianna, and her 5-year-old brother Mark Jr. Each will be remembered at a Mass on Friday at Our Lady of Calvary Church in Northeast Philadelphia.

It was Megan Short's mother, Jacquelyn Massott Campbell, whose worried call to police on Saturday after her daughter failed to show up led officers to the gruesome discovery inside the home. Campbell, a longtime editor at the Bucks County Courier Times, did not respond to an email or Facebook message seeking comment Monday. A man who answered the phone at a number listed for her declined to comment.

Investigators offered no other details and could not say when they would.

"Our thoughts and prayers go out to the families and we ask that you respect their privacy during this difficult time," Chief Berks County Detective Michael J. Gombar said in a written statement. Prosecutors also declined to comment.

Neighbors were in disbelief over the tragedy at Brookfield Manor, the development of about 70 detached houses where, according to one woman, the Short family had lived for about a decade.

News crews and motorists had been winding past the corner house on Winding Brook Drive for several days, eyeing the slain family's Toyota minivan and SUV still parked in the driveway. Some lingered.

"My kids are rocked," said one neighbor a few houses away, declining to give her name because, she said, the media onslaught had been so intense.

She said her young daughter, who used to ride the bus to school with Lianna Short, had not slept at all, tormented by one question: "Why the kids? Why the kids? Why did they do that to the children?"

Mark Short, 40, worked for NVR Inc., a real estate and lending company that serves as parent company for Ryan Homes. A representative for the company said it would have no comment. The manager of the Blue Bell office where Short worked did not respond to inquiries.

Megan Short was friendly, and engaged in annual ornament swaps that featured cocktails and light bites with other mothers in the neighborhood.

Another neighbor who asked not to be identified said she "spoke to her on many occasions, especially during the kid functions in our development. Very sweet girl." She didn't know Mark Short as well. He "didn't come too often to those functions - it was usually just her and the kids."

Many donated meals two years ago, when the family's medical travails were chronicled on a Facebook page called "Willow's Heart Journey."

"Everybody is willing to pitch in when we know a neighbor in a time of need," the woman a few doors down said. "We are all struggling with that. Obviously, there was more of a need than any of us realized."

On the "Willow's Heart Journey" page, Megan Short said she was 19 weeks pregnant when she learned about the girl's congenital heart defect. The left side of her heart was non-functional.

"Willow's prognosis was not good," her mother explained. "We were told to expect her to be stillborn in the next few weeks."

The child was born in the Special Delivery Unit at CHOP and, given a "50/50 chance of her surviving," had her first open-heart surgery when she was 3 days old. In the days that followed she received 16 blood transfusions to cope with complications.

Willow was put on a heart-lung machine designed for infants and immediately listed for transplant, her mother wrote. But the family was told that the average wait for an infant heart was three to six months, while the heart-lung machine could support her for only a few weeks.

"Three and a half days later, in the middle of the night, we received the call that a heart had become available," Megan Short had written. "A family lost their sweet baby and gave Willow the greatest gift that we could never repay them for. Willow received a brand new heart before she turned a week old."

The Facebook page included shouts of support from friends and loved ones of the family.

"This has been a hard road, but this little miracle has taught me more in her short time than I had learned my entire life before her," her mother wrote. "My faith in God is stronger, my faith in others is renewed, and my love for my family is deeper than ever."

A red bumper sticker on the back of the Short minivan touts Mended Little Hearts, a support group for families affected by congenital heart disease.

It was in a "Philly at Heart" blog post affiliated with this group that, in April, Megan Short wrote about her experience dealing with post-traumatic stress disorder throughout her ordeal with Willow.

She wrote that she suffered from "anxiety and nightmares" triggered by smells, hallways - even the beeping sound of a phone.

On the website, which is devoted to families dealing with congenital heart issues, she also wrote that she experienced "survivor's guilt" when children with similar problems from other families passed away.

"I don't think PTSD ever truly goes away but, with therapy, medication, and the right support, I have begun to loosen its grip on me," she wrote. "As I work on my own mental healing, I wanted to share my experience so that other heart parents know they are not alone."

The organization's national program director, Jodi Lemacks of Richmond, Va., said Monday: "We're obviously devastated by this news."

"I am not suggesting [Willow's condition] had any relationship with the sad events that occurred," Lemacks added, "but there is an impact on families that often goes unrecognized."

Even after the successful surgery, the family struggled to get the drugs necessary to keep Willow from rejecting the new heart, according to an interview Megan Short gave the New York Times last year.

One month, she discovered that her pharmacy had mistakenly sent only enough medication for Willow for just 14 days, not the 30 she was supposed to receive.

"Every single month it seems like it's something," she told the Times.

The problems within her marriage also apparently built.

She and a neighbor, Angie Burke, exchanged comments on Facebook on a July 15 Washington Post opinion piece about emotional abuse in a marriage.

"Burke's Facebook account shows that Megan Short commented, 'It really does a number on your mental health for sure,' " the Reading Eagle reported. "Short commented later, 'This is why I am leaving my marriage Angie. 16 years.' " (No one answered the door Monday when the Inquirer knocked on Burke's home.)

Mary Kay Bernosky, executive director of Berks Women in Crisis, said confidentiality provisions prevented her from disclosing whether Megan Short had reached out to the nonprofit abuse services agency for help. Bernosky said she was unaware of any protection-from-abuse order filed. "Days like this are very hard," Bernosky said. "This just shows us how much further we have to go."

On Dec. 20, Mark Short had posted a picture of the couple on his Facebook page. "She's still the most beautiful girl that I've ever met," he wrote. "I'm the luckiest guy in the world to have her as my wife and the mother of my three amazing children."


Staff writers Mari A. Schaefer, Marie McCullough, Daniel Block and Robert Moran contributed to this article.