My DD sleeps in her own bed but is free to come and co-sleep if she wakes (has been since tiny). At around your DD's age she also would play the clown some nights. Our solution was to tell her if she wasn't going to sleep in Mummy and Daddy's bed then she could go back in her own bed, and stick to this. We did have to carry out our thread once or twice (which she wasn't particularly happy about), but it worked. We took the sides off her cot at 16 mths and she wasn't doing it by that stage.