This is a tricky scenario that I see a lot of parents dealing with. They want to move their youngest into a room with their toddler, but are unsure how to sleep train without waking up the older child.
That’s a valid concern, and I wish I had a magical solution for you that would ensure your toddler will enjoy the same uninterrupted sleep that they did when they had the room to themselves, but unfortunately, that’s just not realistic.
(Before I get into this next paragraph, let me just say that I do NOT use a cry-it-out approach when sleep training. I will never ask you to leave a crying baby alone until they fall asleep, if you’re not comfortable with the idea.)
Having said that, sleep training is going to involve some crying. In fact, having a baby period is going to involve a whole lot of crying, so I’m sure that comes as no surprise. And sleep training one baby in a room with another is going to mean some wake-ups on the part of the older child.
But ask yourself, is it better to cause an interruption in this child’s sleep for a week or so in order to get the whole family sleeping through the night, or should we ride out a few years of nightly wake-ups instead? I’m sure you’ll agree it’s an easy answer.
So once you’ve decided to go ahead with the process, it’s time to examine how you can minimize the impact it’s going to have on your toddler, and on that note, I do have some great tips for you.
First off, if possible, start the program in your own room. Put baby in a bassinet next to your bed and, if possible, separate the room by hanging a curtain or a blanket between your bed and the bassinet. It’s not going to look terribly stylish, but it will keep baby from being able to see you, which is important. You could also use an "accordion style" room divider if you have one of those!
Once baby has learned some skills and seems to be able to fall asleep independently, then you can move her into your toddler’s room.
Now, unless you’re extraordinarily lucky, this is going to be met with a little resistance, both from baby and their sibling. It’s a change to the routine and that’s usually going to make bedtime a little harder for your little ones, so try to plan this transition for a weekend, or better yet, a week when you’re not facing a lot of other obligations (preschool, birthday parties, etc.).
Take the time to explain to your toddler what’s going on, and let them know that when baby wakes up crying, you’ll be in shortly to take care of things. The more they understand what’s going on, the less they’ll be agitated by their new roommates nighttime shenanigans.
As for naps, I recommend you keep your little ones separated. Put one in the bedroom and put the other in a Pack n’ Play in another room. The fact is, naps are the toughest part of the program, and you’re probably better off just making an accommodation in this situation in order to ensure they both get the sleep they need.
One last thing to add on this topic... I know some parents tend to take this approach despite having an extra bedroom because they want to hold on to the spare room for their in-laws or other visitors who might need to spend the night.
If the extra bedroom is an option, I strongly suggest you use it. Sleep training when siblings share a room isn’t impossible, but it does add an extra layer of difficulty to the process, and you’re much better off moving one child into the other’s room on those occasions when you have company, than trying to get them both sleeping in the same room on a permanent basis. This is actually what we do in my home. My toddler has his own room and my four month old has a crib in the guest room, for now. Ninety nine percent of the time it's HIS room and way easier to simply accommodate when we have guests.
In short, it’s difficult, but it’s far from impossible, and it’s a much better option than not teaching your little ones to fall asleep independently. I can assure you that the outcome will be worth the challenge.