“Girls wear panties and boys wear underwear,” my 3-year-old daughter, who has affectionately been known as Petunia since she was in utero, explained to me matter-of-factly the other day. “But sometimes girls wear underwear and boys wear panties.”

I never thought a toddler who lately insists on being referred to as Dora the Explorer, and is stubbornly accompanied at all times by an imaginary monkey, would be capable of such insight and, frankly, eloquence. Over the past few months, however, she has proved to be exceptionally adept at expressing herself verbally and otherwise. For better or worse.

When my younger daughter, lovingly nicknamed Peony shortly after she was conceived, was born at the end of August, it was Petunia who helped me realize how much easier the second baby is than the first. Specifically because Petunia has made it so incredibly difficult for anyone to possibly be more difficult than she is.

“Peony is crying,” Petunia has pointed out helpfully on a few occasions. “That means she needs something. Feed her.”

If I weren’t so terrified that Petunia is actually a hitman with explicit orders to take down Peony, I would think her concern for her baby sister is charming. But the reality is that she loves her a little too hard, and as such, the deathwatch has been nonstop. I finally understand why so many families have more than two children — so the oldest can be commissioned to keep watch over the middle child to ensure they don’t kill the youngest. Any extra eyes are incredibly useful in maintaining life in the youngest kid.

If I had known how much easier the second baby would be, I might have had her sooner. Peony eats well (as evidenced by her thighs, which rival the size of the Kardashian’s bank account), sleeps well (praise the lord and hallelujah) and is generally the most precious baby girl since the one in that Visa commercial where she plays with the box instead of the stuff that came inside of it. Just don’t mention that in the presence of Petunia.

“She’s so adorable,” an acquaintance exclaimed about Peony when we saw her in passing as we were out walking a few weeks ago.

“She is NOT adorable,” Petunia said crossly. “I adorable.”

By default is not how I had hoped my second baby would emerge as the messiah.

The lullabies Petunia sings to Peony are just a little too loud, a little too close. The cuddling is a little too smothering. The petting is a little too, well, how you’d treat a dog for which you have a great deal of disdain for any number of reasons, such as bad breath or a habit of breaking your skin with its teeth.

My older daughter, charming as she actually is, is blossoming into how I imagine my parents hoped my offspring would be when I was younger and the undeniable cause of their near-constant headaches: A big pill that causes instead of cures near-constant headaches.

And yet. At the same time, Petunia is abundantly clever and affectionate, giving and seeking hugs, kisses and declarations of adoration at nearly ever turn. She’s also exceedingly bright, eager to pick up as much Spanish as Dora is willing to ask her to scream at the TV in a 25-minute episode. It’s hard to blame one still so little, and with such an enormous capacity for love, for not being thrilled that her world has been turned upside down because of one even littler.

It doesn’t take a psychiatrist to know that Petunia is simply jealous of her little sister. It’s that jealousy that has made life in our house since the arrival of Peony kind of how I imagine it is when you go for a Krispy Kreme doughnut prior to your initial weigh-in at Weight Watchers: frantic and kind of pathetic. It should be sweet, but the enjoyment of the sugary aftertaste only lasts for moments before reality hits you along with the number on the scale, at which time you’re desperate to purge and brush your teeth.

The worst time of day in our house is between 4 p.m. and 7 p.m. Petunia either gets home from preschool or wakes up from her nap at around 4. And that’s when she starts melting down. That’s also the time when Peony starts cluster feeding and/or needing to be held constantly. Which is also when I’m trying to finish up work for the day and start cooking dinner. Did I mention that’s when Petunia starts melting down? It’s like the perfect storm of parenting.

Peony isn’t ever a problem, but Peony is the root of nearly all the problems. She’s like the messiah, except to Petunia, whom if she were just a wee bit more advanced verbally, would probably argue that she’s actually a sign of the apocalypse.

No one said motherhood would be easy. It’s just that in the three years I’ve been doing it, I really had no idea. Until four months ago.

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