I have an 8 month old and a 4 year old. The 4 year sleeps in the bed with me and there is no way that is going to change...I have tried and I am tired of pushing it. The 8 month old sleeps in a crib in my room. They are both great sleepers so I don't want to change that, 8 month old sometimes gets up once or twice, but normally sleeps 6-8 stretch which I am fine with.
The problem: I nurse the 8 month old to sleep - she is pulling herself up and cruising in her crib, so the crib is all the way down at the bottom. I have pelvic and back issues which led to a c-section for her and had an allergic reaction to the stitches - so my back and front hurt and my incision is still healing, so getting her over the crib side (it's a drop side crib too) is a challenge without dropping her. It hurts my back horribly and if I use the side for support it hits my incision. It wakes her up, and she also won't sleep in the crib during the day (I don't know why - I am thinking she can feel me move her to the crib) I can't bring her in the bed becuse of the 4 year old, she flips and turns and kicks, even though she sleeps 12 hours straight, she sleeps above the covers and moves way to much for me to feel safe having the 8 month old in bed.
So....after that long explantation...what can the 8 month old sleep in? A mattress on the floor with something around it? a bed on the floor with rails? She can crawl and she is very active when awake, I am worried about her waking up and falling or crawling into something if I am asleep or not there. But I have no idea if there are other options besides a crib at her age.
Have you heard of Montessori rooms? Maybe that would work, at least for naps.
I am so sorry to hear about your pain. I just finished weekly physical therapy for Pelvic Girdle Pain, so I can relate to how hard pelvic and back issues are. We have our LO in a crib that is side-carred to our bed. He can sleep without sheets or pillow near him that way. Another idea is keeping your DD in bed with you, but give her different bedding so that your sheets are not moved to impact the baby but still keeps her in bed with you. Perhaps a fun sleeping bag that you and she could go and pick out together or even a pretty sheeet that you sew into a bag for her to use.