I.M.
She sounds very normal to me. She is eating, and drinking fine. You mentioned that she is also drinking water and juice from a sippy cup but that it is not enough for what you think she should be drinking; but it sounds like it's enough for her. Try to weight her in the mornings every day for at least a week and see how she is doing. She is eating very well, so she is going to drink a little less. Don't worry so much, what she is drinking is plenty for her. Why don't you call her pediatrician and see what he/she tells you? That might give you a better piece of mind.
Blessings