why does a child keep wanting to behave like a small baby?
My child is always wanting to know how she was as a baby, details about babies in general and acts like a baby make cooing noises, otherwise she is fine when with here friends is has just turns 11 has been like this for the past 3 years?
Perhaps your child and you can discuss this through art or storytelling to help her feel safe in a way where she can discuss her birth story. She also may be reflecting what others have discussed with her, so now may be a good time to ask if others have had siblings just born, etc.
Praising her as a mature tween and discussing how much you enjoy her talents and growth may help her to be more assured in her changing body and at a time where she is more emotional due to life changes.