I don't know of any books, but I can suggest something that is free! I really think it's so important for your daughter to see you love yourself. She takes her cues from you, and if her mom is relatively happy, well-adjusted, and seems content with who she is and how she looks, your daughter will accept that as the norm and follow your lead. I have a 3.5 year old and I have started to try to make sure I compliment her often, talk to her about good foods to eat and exercise, but show her that I am human too. It is SO important to me that my girls be confident, I hear you there. As someone whose mother was not very happy with her looks or herself, I grew up thinking that it was just the way women operated... it wasn't until I was older that I realized many women out there accept themselves and their bodies - this was a novel idea for me! I have worked my adult life to accept myself and my looks, and of course it can be tough sometimes (like when I get down about myself for the lovely c-section overhang - another subject entirely!), but I know my oldest sees me as strong and confident, and I have to hope that this will help shape her self-esteem later on.
I'm sure there are books out there that will address the concerns you mentioned. Just do a google search or search amazon.com if you haven't already. You sound like a great mother and I'm sure you are setting an awesome example for your girls! I bet they are/will be just fine! I was a little scared when I found out I was having girls because of all these types of issues, but now I think it's the best thing that could have happened to me. It is kind-of righting some of the wrongs I have gone through in my life. I hope this helped somewhat!