I co-slept with Seren but she was also usedtogoing into her crib and cot too (she would go in there at the beginning of the night then comeinto bed with me when she woke). She sleeps in her own bed, and doesn't stir all night. If she is feeling unwell or wants reassurance she will come into our bed but this is very rare, and I treasure these snuggly moments.
Cally has been in my bed since she was born, it just felt natural to have her there. I am not concerned at all that she might want to stay in our bed, if she does stay in longer then Seren I am fine with that as before I know it she will be all grown up and gone. Last night Seren came into the family bed at 2am,and I had her and Cally snuggling up to me, it was fab.