hi Pink Jenny, thought I'd post here instead of the other thread. This will be an epic explanation of our situation!
We co-slept accidently too from the age of about 4/5 months when DD's sleep was awful and she'd wake frequently and feed frequently. We did this for about 4 months, mostly sleeping with her on the outside with a bed rail then me and DH. We did this comfortably until she started to crawl, (about 9 months I think). At this point I woke more frequently worrying about her falling off the bed than I did because she was waking me so we'd settle her on the bed and when she was asleep transfer her into the cot. When she woke in the night I'd roll out a matress we'd got from a sofa bed and snuggle up with her on that.
After some weeks of this I realised that this was a very uncomfy option so bought DD her own double matress which we made up like a bed on the floor. So from about the age of 12 months she had her own bed. I dismantled the well meaning cot.
We would always lay with her while she went to sleep, leave when she'd gone to sleep and I would just hop in alongside her when she woke in the night. The time that she went to sleep and woke started getting longer and longer and she has just consistently started sleeping through (although has the odd night and still gets up very very early 5.15 today) and in the last two weeks I've been able to put her to bed and leave the room with her falling to sleep on her own.
She has done this all on her own, at her own pace and is happy. I really think it's a maturity thing. I still jump in with her if need be in the night but it's probably been one night in the last week.
In answer to your question on the other thread. I'd go to bed at maybe 9.30-10 ish when cosleeping but I do remember frequently going to bed at 8ish if she wouldn't settle and reading in bed. We'd have nights where we'd be up and down all evening but I know people who don't co-sleep and have the same problem. Personally, I don't think it's the case.
On the whole, the really unsettled nights and those nights when she was awake for one or two hours at a time were mostly teething related. She's just cut her canines and her sleep got so so much better after they arrived. We have also noticed that developmental phases can also cause 'set backs' ie learning to pull up to standing was a nightmare because she almost had a compulsion to stand as soon as we laid her down.
I hope this has helped