I've always known what it's like to have a great mother, but I had no idea what it's like to be a great mother. Having one dog can't really approximate what it's like to be a mom.

That takes at least three dogs.

As you may know, my mother was recently traveling on tour with her latest book, and it was a grueling schedule: a different city every other day, high-energy signings, meetings with booksellers, and greasy airport food. She loves it, but it's a tough job.

Still, it ain't nothin' compared with being a stay-at-home mom.

I should know. I was taking care of our three dogs while she was away.

In addition to my own dog, Pip, I had two of my mother's dogs - Little Tony, and the new baby, six-month-old Peach. I'm happy to help my mom whenever I can, so I told her it wouldn't be a problem. But it was much harder than I anticipated. It was like caring for human children.

Maybe it was the diapers.

But I'm getting ahead of myself.

I grew up as an only child, but I'd heard the cliches about sibling dynamics - the oldest golden child, the attention-loving baby, the overlooked middle child. I never knew they were true.

Peach is tiny, adorable, and accident-prone. I carried her wherever I went and otherwise kept her on my lap so I could make sure she didn't get into stuff, put anything in her mouth, or pee on the floor.

Pip, my oldest, is the best-behaved and my first love, so he was on his own with occasional praise for being a very good boy.

As for Little Tony, the middle child, I forgot he existed until he did something bad.

They have therapists for dogs, right?

While I struggled to divide my time and love equally, I nearly missed a major milestone in my little girl's life - Peach's first period.

I know, I couldn't believe it, either. But call it a mother's intuition, or call it a red spot on my couch, I just knew.

But what do you do when a dog becomes a woman?

Are you there, God? It's me, Francesca, and I have this dog. . . .

The first problem is that Peach is tiny. The puppy weighs less than 10 pounds, so I had to try a slew of pet stores to find doggy diapers small enough to fit.

Not that she allowed them to stay on her body. Peach tried to pull, squirm, and chew herself free from her diaper.

Babies are so fussy.

During the brief moments when Peach tired and left the diaper alone, Tony bothered it for her.

Mother's little helper.

On top of it all, I got sick as a dog, no pun. The unpredictable spring weather left me with an awful head cold. But as every parent knows, moms can't get sick. Rather, if they do, it doesn't count.

I needed Sudafed but I didn't want to leave the little ones at home, so I found myself standing in the pharmacy line, holding the puppy on my hip, with the two others wrapped around my legs.

People were staring, but I didn't care. All I could think about was how much time I had before Tony needed to go to the bathroom, how many diapers we had left at home, and whether Pip ate a wad of gum that I could have sworn was on the floor a minute ago.

I had crossed a threshold. The dogs had become my priority.

Although dogs, even three of them, aren't the same as children, the priority shift is the same as every mother's. My mom changed her career, her entire life, to stay home with me. She has put me first in every decision she's ever made. And as result, she is the first person I turn to in every one of mine.

For Mother's Day next week, I want to thank the mothers who do the difficult, tiring, messy, comical, selfless work of putting us first. You're number one to us.

Until we have kids of our own.

Just like you taught us.

Happy Mother's Day.