Ok I don't really use Picasa, but I do...if that makes sense
That is where all my pictures are stored for my blog with blogger. Now when I upload to it, it's always through blogger and the pictures are all already resized to web size (usually 600x480). So I just testedit by uploading directly at Picasa with an unedited photo (sized 3456×2304 pixels & 1.07MB). Picasa kept it that size!!
So I would suggest you have her check her camera settings....it might be as Debra stated and she is shooting on to low of a setting!!!
Hope I helped just a little Jamie!!!!