I used to co-sleep with DD2. I really left it up to her and as she was a pretty still sleeper it was never a problem. She was always comforted being close to me and I really enjoyed having her in bed with me, it was never a full time thing although when she was 2 and her sister was 4 I would let them sleep in my bed whenever I was alone. Even now if DH is away for work DD2 will come in bed with me and she is now 9 years old. I think it's just something she finds comforting when she is able to sleep with me again. Usually before she goes to bed and I'm laying down in my bed she'll come and lay beside me and we'll chat together and watch a bit of TV together. I really learnt a lot from my second daughter in that I gave her the comfort and security that she needed (instead of listening to the "take the hard line" type people) and she really benefitted from it and that makes me happy.