Miriam has been rolling up a storm lately. (Side note: I guess I say that phrase a lot because lately when he hears her coo, Niko says, "she talkin up a sorm mama!")
I hardly lay her on her back before she's rolling to one side and over to her tummy.
She's not as good at rolling to her back, but she does it sometimes.
And finally, a video of how sweet and shouty she gets when she's tired: