My DD is almost 21 weeks old. She is trying to sit up at the moment, and when gently pulled she'll sit up and then pushes herself to a standing position (obviously supported by somebody).
She seems most happy sitting up or on her feet. She is showing no sign of wanting or trying to roll over. My DH and I have been rolling her on a blanket, and we put her on her tummy a lot, but should be we concerned that she is trying to sit up and not roll?