My DD is 7 weeks old, and last week she had rolled over. Being a STM I figured it was probably an accident, possibly something made her jump and she ended up on her back, because DD1 didn't roll at all until at least 3 months. But, all week, during tummy time, she has been a rolling son of a gun. She isn't on the ground for more than a minute, and she is on her back, smiling blissfully. Today alone I counted 12 times. I am pretty impressed with her motor skills, but I am also kind of hoping it isn't a sign that I'll have two very mobile children, as DD1 is a climbing, jumping, running, hyper active child. I am not sure I could handle keeping up with 2 of those haha.
Re: Rolling
Our pedi said the same thing. She said most likely it will stop when DS gets bigger and then he will start again in a few months, but this time it will be purposeful.