Editor's note: This article was originally published on Merely Mothers. It has been republished here with permission.

Dear Friend,

I've been thinking of you, as you welcome another little baby into your life. There's nothing more exhausting and exhilarating than ending those nine long months with a precious new spirit that will forever shape the face of your family.

You're not new to this whole motherhood thing. You remember the sleepless nights, the mountains of laundry, the explosive diapers, and the spit-up stained carpets. And you must not have forgotten the sweet smell of your baby's freshly bathed head, the warmth of her tiny little body as she curls up to rest on your shoulder, and those sweet fingers reaching up in search of yours. So many parts of this experience will feel familiar to you, but in truth, everything is different now, because you're bringing this baby into a home that already has a baby in it.

Nothing can really prepare you for life with another child (just as nothing could prepare you for the first), so I won't even bother to fill your head with nonsense about sleeping when the baby sleeps, bonding quietly during feedings, etc., etc. None of these things is even possible when you're caring for a newborn and another child at the same time.

But since the experience is so fresh in my mind, having welcomed our second baby just nine months ago, I'd like to impart a singular piece of wisdom that was hard earned.

This is not just your baby

Sure, you and your husband created this baby. You carried it for what felt like an eternity. But really, by creating another life, you've drastically changed the dynamic of your family and turned your first child's world upside-down. She is powerless in this scenario, except in one way: how she relates to that new baby.

When you return from the hospital, groggy and achy, bear in mind that your first child has to be your focus. Sure, the first time around, it seemed like your newborn was all-consuming, but you'll see, they're actually pretty easy. New babies sleep constantly, eat briefly, and at worst, just want to be held. So strap that baby onto you, get down on the floor, and play with big sister, who must feel so overwhelmed by the changes you've brought upon her.

Try to maintain a sense of normalcy for your big kid. Stick to routines, keep scheduling playdates, make time for trips to the playground, and find special time for her favorite activities, because really, your baby will just tag along. And showing big sister that the world hasn't stopped just for the baby will lessen the resentment.

But more importantly than that, show big sister that this is herbaby, too. In the hospital, before my daughter, A, came to visit, we sent Baby J off to the nursery, so that big sister could go and retrieve her. We wanted to minimize the shock of seeing her mommy holding another child and give A a sense of her new charge - her responsibility to care for her new sister.

From that moment on, we did all we could to show A that Baby J was hers, letting A play with her; help dress her, bathe her, feed her, and change her diaper; even pick out her clothes. The baby was not something to be threatened by, but a sort of "project" she could help with (because let's face it, these are the terms in which 2-year-olds think). I've seen how much this attitude fostered caring behavior in my big girl.

Of course, sometimes all A wants to do, even today, is be a baby. And we go with it. Sometimes when the baby cries, big sister pretends to cry. When we change the baby's diaper, we may also have to pretend to change A's. Sometimes, A wants to be held and rocked like a baby, and we're happy to comply (how often does a squirmy 2- or 3-year-old let you do that?).

Not everything has gone smoothly here, and there were definitely a few months when A's behavior was indicative of a child seriously bent out of shape about the new baby. But one thing I know we did right was to let A see that this was _her_sweet little baby to admire, and care for, and love.

I wish you good luck as you adjust to life as a mother of two and begin this balancing act of caring for your new brood!