As our girls are getting older, their anger is getting more personal.

Back when they were toddlers, they’d howl and scream and throw themselves on the ground when they were upset about something — like all toddlers. But their howls and screams weren’t personal: they were cries of fury directed at the universe, existential angst. WHY can’t I have what I want RIGHT NOW?!? Even when I was the cause of that angst, I wasn’t the target of their anger. Their tantrums launched them into another realm, and even their garbled yells rarely, if ever, included my name.

That’s all changed in the past six months. Now, when I say “no,” or look askance, or fail to use the nicest possible tone, my oldest daughters are quick to make it personal: “You’re being mean. We’re getting a new mommy!”

(Note on the idea of “getting a new mommy,” which seems particularly cruel: this idea did not originate with my girls. Maybe, just maybe, it’s something that I suggested once in an effort to lighten up a heated exchange….but the girls latched on to the concept).

I suppose another way of saying this is that, as my girls grow up, they’re learning how to hit where it hurts. I’m so proud.

Not for the faint of heart, this parenting gig. It’s incredible how quickly children turn from innocent, adorable, dependent infants, into such willful, flawed little people. NOBODY warned me that adolescence begins during preschool, but it does. Oh yes, it does, complete with the pouting, eye rolling, and shouting “FINE!” while stomping upstairs.

For a while, I responded to the “You’re being mean!” complaint by trying to reason with the girls. “I’m not being mean,” I’d say calmly. (The calm is important; I’ve learned that if my anger rises to meet theirs, things will only escalate and I’ll feel terrible afterwards. This way I can say, “Well, at least I remained calm.”) Then I’d point to the evidence; almost every single time I was accused of being mean, I was, in fact, engaged in activities that would suggest just the opposite. Like driving the girls to get ice cream. Preparing dinner for the entire family. Getting everybody dressed to go out.

But of course there’s no convincing a preschooler that you’re not being mean. We’re not talking about logical people here. It doesn’t matter that I’m doing non-mean things for the greater good; if they’re not getting what they want, when they want it, I’m mean. I could be discovering the cure for cancer with one hand, but if the other hand isn’t putting exactly the right ponytail into my daughter’s hair, I’m “not nice.”

Finally, one day when daughter #1 pulled out the “You’re being mean” card, I responded, “You know what? That’s okay. It’s not my job to be nice.”

That surprised us both for a minute. After all, I’ve spent my whole life trying to be nice; my attempts to be nice, to make everybody like me, have defined my character for most of my life — and have been at the root of some of my very worst choices.

But after I said it, I realized that I was right: being nice is NOT part of my job as a mother.

It’s my job to LOVE my children. But “love” and “nice” are not synonyms.

Here’s what I think love looks like: keeping my children alive (to the extent that I can control), nurturing their bodies and minds and spirits, encouraging them to become the best versions of themselves, and giving them the tools to grow into independent adults. Nothing in there about “nice.” On the contrary, the items on that list will probably require a whole lot of behavior that, at the time, looks “mean” to my kids.

What a concept. This is something that does NOT come naturally to me. But I’ve kept repeating, “It’s not my job to be nice,” as a reminder to myself and to my girls of what love really looks like.

One more thing: The other night, as I was putting them to bed after a day filled with “mean” accusations from my girls, Fiona asked what I planned to do for the rest of the evening.

“Oh,” I said, “I think I’m going to read this great new book I just got. It’s called 101 Ways to be Mean to Your Kids.”

“MOMMY,” she said, and in the dark I could hear her eyes rolling.

But I think she got it. It’s not my job to be nice, but it is my job to help us all keep a sense of humor about life. I see it as a favor to that new Mommy they’ve ordered, whenever she arrives.