My grandmother had five children and more than a handful of grandchildren, which made her a hot commodity after she retired from teaching.

She spent a fair share of her senior years ferrying herself from one house to the next, as one of her children went off on vacation with their spouse, or another was rushed to the hospital to have another baby.

She was an awful lot like Mary Poppins, but instead of an umbrella she brought books in her suitcase and taught us how to read.

I am reminded of her this week as I am off visiting my daughter and her family as they welcome their first child into the world.

It’s a learning process to insert yourself into someone else’s family, especially someone you used to change, care for and discipline yourself. But if I play it the way my grandmother did, I’ll be fine. She circled between the four families so effortlessly that I am trying to use her well-tested principles to guide me.

Rule number one is perhaps the most important: “What happens when Grandmother is here stays with Grandmother.” That means that if she cycled between two houses in one month, she would not bring any negative reviews with her. If my cousin Michael, for example, lit the curtains on fire or threw the car keys in the dumpster down the street, we would not hear of it when my grandmother got to our house.

What she knew is that living with a family gives you front row seats to their lives. You are the spectator on the couch or in the spare room who sees and hears it all. It’s a privilege to be let in, to eat popcorn from the stands and watch the show. Therefore, you must not betray their confidence. You must allow them to be themselves without fear they will make the headlines in the proverbial family newspaper.

Rule number two is to let the new mother find her way. Since there have been trillions of mothers throughout history, it stands to reason that most found their way without doing too much damage to the human race. Through my grandmother’s example, I understand that I am here to take care of the new mother—not to take over the new baby, as hard as it is to keep myself away.

And rule number three is that I am not a parent in the house. I am a guest. As much as I might like to impose my views about bedtimes and lasagna ingredients and turning off lights in the hallway, it is not my place. My time for imposing my views on my children has passed; I can only hope that I did well enough when I had the chance but today is no longer that day.

When my third daughter Maggie was born nearly a month early, we were all in a panic. On such short notice, who would come and help?

It was decided my grandmother would come, even though she was approaching 80.

I don’t think I will ever forget her gentle presence in those days after my daughter’s birth. No longer capable of whipping up family-style meals or taking the stairs two at a time, she played the role of the matriarch from a comfortable chair in the living room, reading to the older two girls, or spending long hours with the baby on her lap, rubbing her back.

She passed away a few years ago at the ripe old age of 96, and I miss her this week as I learn my role as the wise old woman in someone else’s house.

And as I go about the world, I keep hearing grandmothers referred to as all sorts of things, like “Mimi” or “Gigi” or “Grammie,” or some such name.

Since I was to be a young grandmother, my daughter decided I should be “Mimi.”

For the life of me, I can’t seem to make it stick. I had such wonderful grandmothers that I consider it a privilege to be called that name.