Denise, is there any way to get her to put her back to the sun? If so you could use you pop-up flash for fill (just dial the flash comp down) or an on camera speedlight. If you wanted to take a little more time and set up, then take Sean's advice (he knows much more than I do about OCF). I have to use my speedlight on camera when chasing my boys around when I try to photograph them with no help and the results aren't awesome but are still pretty good. You wont have to worry about red eye because it is already bright outside.

Most of these are taken in that manner...my family photo shoot.