At what age is it safe for siblings to cosleep in their own room?

[moonjunio]

I bedshare with my 9 month old, and have a 3 year old in her own room.  Hubby is getting tired of not having our own room/bed, so we've thought about putting the crib in our preschooler's room.  The baby starts the night in her crib and could probably be fine in there all night if I just get up to nurse and put her back down.  However, I'm concerned about what happens a few months down the road, when we would have a toddler and a preschool sleeping in the same room.

I know some people use cribs until their kids are 2 or so, but I prefer to convert the crib to a toddler bed (or just mattress on the floor) as soon as she can get in and out safely.  So, right around when she starts walking.   I'm worried that our preschooler might get in bed with the little one and snuggle her... too much.  

The older one has always been very loving with her baby sister, but with boundary issues.  I have to remind her not to put weight on the baby, don't hug her neck, etc.   That said, the 3 year old is a very sound sleeper who doesn't get up in the night anymore.  

What do you think, can a 1 year old and 3 year old be alone in the same room together all night?  If not, what age do you think is safe?  Is a crib necessary to keep a toddler safe from big sister?

[Mom31]

I am not sure but wanted to offer support. Many parents put two kids in the same room... My kids shared a room for a few years but were older and I would find them in bed together- ages like 3 and 5. It was sweet.  I think safety needs to be your first concern of course... hope you get more replies.

[moonjunio]

Thank you :-) I know sibling room sharing is sometimes the only real option - maybe that's why keeping kids in their cribs so long is popular?