Amelia rolled for the first time, from her back to her front, on April 11, 2002, just two days before she turned five months old. This is a quicktime movie (2.4MB) of her rolling on the following day- all day, if she was put on her back, she would immediately roll to her front (unless the camera was on her, then she mostly smiled sweetly and stayed put, but we eventually got this clip).

That's Sara in the background, giving Amelia her cue, and Big Ben, six months old, looking on. He's a master of rolling and didn't take much interest in Amelia's efforts.