Rolling over.

My 6 month old just wont roll over. She has done it one time without help and that's all. It would really help if she did because she is a very restless sleeper and wants to go back to her side after being on her back and she gets soo mad cause she can't do it. She sits on her own, eats well, even feeds herself puffs. Pulls herself into stand position but will not roll or go into crawling position. 😓 anyone else's baby this way?