WHEN JULIA Shaw joined a parents' meet-up group about three years ago, there were five moms meeting for "babies and beer" on someone's front stoop.

Today, that group has evolved to more than 100 members, with organized kids' activities, adult nights out and information sharing on everything from pediatricians to schools.

"It represents a fraction of what's going on in our neighborhood," said Shaw, 34, who lives in southwest Center City with her husband Bob, 34, and daughter Lucy, 3. "We get so many requests for membership that I can't keep up and I'm constantly meeting new parents who aren't part of the group yet."

Center City, it seems, is going to the kids.

While recent census data shows more twenty- and thirty-somethings settling between Spring Garden Street and Washington Avenue, the Delaware and the Schuylkill rivers, it also reveals a another sort of youth explosion: That among the preschool and school-age set.

More than 17,100 children were born to Center City parents between 2000 and 2008, according to analysis by the Center City District. Compare that to 1990, when the Health Department tallied 272 births to Center City parents.

The 2010 U.S. census data also shows more younger children, with an increase of 3.5 percent in the under-5 category.

Center City has definitely become a more kid-friendly destination in recent years, with the opening of more child-centric businesses and youth-oriented spots like Franklin Square Park.

Perhaps one of the most telling signs of change?

The former Signatures strip club at 13th and Locust streets is poised to become Nest, a three-story, 15,000-square-foot "children's enrichment center" featuring an indoor play area, group classes, a photo studio and a boutique, plus a restaurant run by the folks behind South Philly's Green Eggs Cafe, a partner in the project said.

Set to open next month, the complex is situated at a corner that only 10 years ago saw more prostitutes than prams.

Child 'hood

The Center City of 2011 is more resident-friendly than the neighborhood was 30, 20, even 10 years earlier, said Paul Levy, president of the Center City District. Besides more stores, services and restaurants, there are more kid-focused businesses.

"You have an increasing number of families with kids and retail is responding to those market conditions," Levy said. "All you have to do is walk around and there are so many more strollers than there were ever before."

That's for several reasons.

Crime is down. Center City public schools are seen as improving and are drawing more of their students from their immediate neighborhoods.

A wealth of new charter schools offer families an option besides private schools.

The CCD operates kidsincentercity.org, which started as a schools website and evolved into its current form in 2009 in response to demands.

"We started getting more requests for good places for birthday parties and kid-friendly restaurants and summer camps," Levy said. "There is clearly a trend of parents wanting to stay in the city and raise their kids . . . This is not to say the suburbs are obsolete but the city is no longer automatically off the list."

Jackie Promislo, a former lawyer, opened her Washington Square store Lolli Lolli in August 2007 when, she said, no other children's stores were on the east side of Broad Street. Even when her windows were still boarded up during construction, "people would come in and buy stuff without a register," she said. And business has only gotten stronger.

"It's overrun with children and we love it," Promislo said.

Promislo lives with her husband in Society Hill, where their two children attend St. Peter's School. He works from home. She works a few blocks away.

"We feel we can be more actively involved in our kids' lives," she said. "We're not in the car driving around."

The absence of a driveway culture is one reason multiple parents cited when asked why they were keeping their kids in the city.

"It's about being closer to your neighbors and knowing your neighbors as opposed to going up your driveway and into your house," said Amy Rivera, a mother of three who lives in Queen Village and who organizes Mario Lanza Park's weekly "Kid Fest" celebrations in June.

In some cases, the parents want their children to have more cosmopolitan upbringings than they had.

Kelly McCabe, 39, of Bella Vista, grew up on the beach in Florida. She's watched as friends have packed up and moved when their kids got to school age, but she's inclined to stay with her pair, ages 7 and 4.

"My kids walk everywhere and have a real sense of their neighborhood," she said.

"I like that they're exposed to all shades of people and types of families and they're not surprised by it. It's how the world is."

More parents are also sending their children to public schools. For example, at Center City's McCall Elementary, enrollment is up 12 percent since the 2006-'07 school year. Meanwhile, at Queen Village's Meredith Elementary, enrollment is up 16 percent since that time. The majority of students who live in each school's borders attend the public school, according to school district data.

"The reduced class size coupled with neighborhood enrollment has resulted in a decrease in the number of students that can be accepted from out of the feeder area," Philadelphia School District spokeswoman Shana Kemp said.

Len Lipkin, one of the founders of phillyschoolsearch.com, said that across the city, more parents are becoming involved in the public schools. School district data supports that.

"I think people are excited about Center City schools," he said.

"There are some concerns about what impact there's going to be from all the budget conversations going around, but the same things are happening to schools all over the city."

Leslie Bari, co-chairwoman of the annual Little Friends of Rittenhouse Square Festival, noted that there were more private schools at this year's event, including schools from the suburbs.

"It's interesting that these schools think this is a great venue for them to be in to reach their target customer," said Bari, whose 6-year-old daughter is going into first grade at Penn Charter, where more than a quarter of her class is from Center City. "People are definitely staying longer."

Sonia Nofziger Dasgupta, president of the Washington Square West Civic Association, and her husband welcomed daughter Kiryn four months ago.

They're already talking which school, but not which suburb.

"We're pretty committed to it," she said of city living. "When we were younger, in our 20s and 30s, all of our friends who had kids moved, without question, to the suburbs. Even some we thought wouldn't, did."

But a core group of their friends have stayed and have committed themselves to helping the city get better.

That means civic involvement.

"If you look of the board of Washington Square West, there are many of us with young children, which was never a thing before," said Dasgupta, who declined to give her age.

"You can't get around Whole Foods because of all the strollers. It's a more affluent kind of parent."

In anticipation of Lucy's school days, Julia Shaw and her husband are getting involved at Chester A. Arthur, their local school.

They're also banding with other parents to improve a local recreation center that needs a boost.

Said Shaw, "You have to be committed to it."