I believe in science.

Except when it comes to Mother Mary.

I always think of her this time of year, because she passed away five years ago, on Palm Sunday.

Yes, I’m aware that the date of Palm Sunday moves, so that it’s not the actual day she passed, which was April 13. But it’s so Mother Mary to remember her on the holiday, and I’ll explain why.

She was only 4 foot, 11 inches, but her personality was 10 times her size.

I love talking about her, which I just did, on a book tour. I’m supposed to talk about my new book, Someone Knows, but I always end up telling funny stories about her, and, oddly, they all involve the weather.

I tell the story about how she was the only person in South Florida who felt an earthquake that had occurred in Tampa, a fact proved by a call she had made to the Miami Herald to report the same. When the TV news van went to her house, they called her Earthquake Mary.

Which she loved.

I tell a story about how I made her fly north to get out of the path of a hurricane, and when she was interviewed about it at the airport, she said, “I’m not afraid of a hurricane, I am a hurricane.”

I tell a story about the day of her memorial service, when it rained so hard that my entrance hall flooded, which has never happened before or since.

And then this Palm Sunday, she sent me another weather-related sign.

I was sitting on a plane in St. Louis, headed for Chicago, when we heard that there was a sudden snowstorm blowing into Chicago.

In the middle of April.

I know it snows a lot in Chicago, but not that much in April, and this storm was unexpected. My flight and others were delayed because the Chicago airport was putting a ground hold on all flights, so we sat on the plane and waited.

And waited.

It turned out 4,000 flights were canceled that day, and mine was one of them.

Unfortunately, I missed my book signing in Chicago.

My apologies.

And I thought of my mother, which is when I wondered whether, in fact, that was what she’d wanted all along.

Mother Mary was the youngest of 19 children, so we can guess she didn’t get much attention. Even now, I think she’s saying, “Look at me.”

“Think of me.”

"Remember me.'

Of course, I need no reminder, nor do you, to remember those you loved and lost.

Holidays are bittersweet for those who have lost people on or around them, but there’s a part of me that thinks Mother Mary likes being remembered on Palm Sunday.

An extraordinary day for an extraordinary woman.

She loved whenever Francesca and I wrote about her. You may remember when Philadelphia magazine published its Best of Philadelphia awards and gave “Chick Wit” an award: for Worst of Philadelphia.

Thanks, Philly Mag.

I’m still laughing.

Last.

Mother Mary happened to be visiting when I got that award, and she was very disappointed.

Because it didn’t mention her.

Thanks to all of you who like the stories about her. Many of you have been to my house for our Big Book Club Party and were as loving to her as though she were your own mother.

With profanity added.

Mother Mary bathed in your affection and talked about you readers all the time. You gave her a gift that she didn’t even know she needed.

A spotlight.

In my opinion, every mother deserves one.

Mother’s Day may be around the corner, but, honestly, I don’t think we give mothers the credit they deserve.

They were the invisible force of nature behind all of us, and if we were lucky, it was a fair wind, not an ill one.

I was lucky, and so was my brother, Frank.

Mother Mary was the most loving of mothers and adored being a grandmother, too. I love when Francesca writes about her, because though we know how much grandparents adore their grandchildren, it’s not often you get to hear how much a grandchild loves a grandparent.

Even more.

We call Francesca the Grandmother Whisperer, because my mother would do anything if Francesca asked.

But not if I did.

Because Francesca asked, Mother Mary even went to the fireworks on July 4, and you haven’t lived until you’ve sat under an exploding sky with your vaguely combustible mother.

When Mother Mary was in hospice at our house, Francesca was at her side, caring for her, talking with her, and doing my mother’s nails, a loving act made more poignant by its circumstances.

Mother Mary used to joke that when she passed, she wanted a mausoleum.

At least I think it was a joke.

She was proud of herself.

She stood up for herself.

She tried to get the best for herself and her family.

She loved people. She could not walk into an Acme without greeting the produce guys, whom she knew by name.

She struck up conversations with every shopper.

She played peekaboo with every baby.

She made life fun.

If Mother Mary grounded 4,000 flights, she had a good laugh over it.

So did I.

Happy Easter, Mom.

We love you.

Look for Lisa and Francesca’s humor collection, “I See Life Through Rosé-Colored Glasses," and Lisa’s best-selling thriller, “Someone Knows,” in stores now.