We have a very small house. My toddler is going to be 23 months when my daughter is born in November. We are considering they share a room, but my toddler does not sleep well and is awoken easily. I am concerned that my newborn will wake her up in the middle of the night and she will become jealous when we take the baby into our bed and leave her to CIO in her crib every two hours...currently, we sometimes let her come and sleep in our bed with us when she cries in the middle of the night...
Do any of you have this issue or have you tried this and it worked? Did it fail? Why or why not? Did your toddler grow jealous of the baby because of this?

Re: Should a toddler and newborn share a room?
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But anyway, it might work but I personally would wait until the newborn is sleeping long stretches. It might just be me but I was quite paranoid about having such a new baby in a room alone that young.
Maybe try keeping the baby in your room for a while or putting the crib in another room near yours (I.e., living room) until you can figure out the logistics.
What I am doing is putting a crib in our room and then will transition baby to their own bedroom around 5-6 months. In your case since there's not an extra room then I would be waiting until baby is down to 1-2 wake ups before transitioning them to share a room with their sibling.
You also have no idea what kind of baby the new one will be. My daughter was a terrible sleeper. She did not string together more than an hour or so of sleep at a time until she was almost 7 months old. Having them in the same room over night would have been a disaster. Once she was a little older, they shared and did just fine. We just had to be really careful to go and get her right away as soon as she woke up fussing.
Sleep training her was another story, though, because we couldn't exactly let her cry it out with my son in the same room.
We were never really concerned about my son climbing into my daughters crib or messing with her too much because it just wasn't his personality--he pretty much didn't notice/ acknowledge her existence until she was moving around and interacting with him a little more.
My girls have shared a room since DD2 was about 3 months old. DD1 was 22.5 months old when DD2 was born. We kept the baby in our room for the first 3 or 4 months and moved her to the crib in DD1's room when she out-grew the cradle. Both of them have always been really good sleepers, so we had no problems with them waking each other up. DD1 could sleep through anything, but DD2 was a much lighter sleeper. So we just put our oldest to bed first, and then put the baby to bed later when we were ready to go to sleep too.
For the middle of the night, wake-ups, we had a recliner in their room, so I just nursed her there and tucked her back in. I didn't need to bring her to my room at all after we moved her. I don't remember DD1 ever waking up for that, but if she had, I probably would have let her come and snuggle while I nursed her sister, and/or tucked her back in with a kiss and a snuggle when I was done feeding the baby.
Naps weren't a problem either. DD2 napped best in her room with everything dark and quiet, so I let her sleep in their room, and DD1 got to nap either on the couch or our bed.
I didn't have to worry about her climbing into the crib until she was older...like 3-4, and by then DD2 was big enough that it wasn't that worrisome. DD1 figured out that babies needed to be treated very carefully pretty quickly, and she was rather rough and tumble at that age. I think it's something you have to teach them, but it's not something that's completely beyond their abilities to learn.