For posting online, the number of megapixels is unimportant; any camera will do. As far as shooting in poor light, she would be better off buying some inexpensive studio lighting than trying to buy a camera that works well in poor light. Even the best compacts can only do so much before using the built-in flash, and built in flash almost always makes people look not-so-good. Regardless, for under $500 you can get any of the top compacts: the Canon S95, the Canon G12, the Panasonic LX5, or the Samsung TL500. All but the Samsung have HD video FWIW, they are all 720p, not so-called full HD cameras...but honestly, you probably wouldn't ever notice the difference). The Canon S95 is the most compact, but the G12 and Panny LX5 have hot shoes for adding a flash; an advantage since you can get a flash that can tilt/bounce its light for better results.