haha, i just bombard her, and take 800 pics. you're bound to get a few you like. also, see if you can find a camera with a faster shutter speed; you don't want her to move between your finger on the button and the click. i know some cameras also come with a mode where you can take a few pics in rapid succession, so you get like a flip-book, and it makes it easier to take a pic in case she does move.
ha ive just got a good pic ov the boys ive had them out for their play time and an hour later they are so tired! so they lay next to each other and i got photos , just got to try n upload them now as they are on my moms camra not mine!