My eldest dd used to complain of what she called "growing pains". This went on for at least a yr and disappeared only when I started giving her vitamin D and cal/mag. Not sure if this is what's going on w/your dd? Has your dd taken any falls recently? Toddlers can get micro-fractures though I'm not sure that this is common in the thigh?
Once she stopped nursing she was never really a big milk drinker and I realized yesterday that she isn't really drinking any milk these days. She eats lots of yogurt and cheese but she doesn't seem to be taking in much liquid. I think tomorrow I am going to work on getting her to drink a bit more and see if that helps.