It definitely sounds like you're doing what you can to help!
I would keep giving her those "p" fruits - pears, peaches, prunes, apricots - as they will help move things along. Diluted prune and apple juice can be helpful too, as can just plain water. I don't think that you have to worry about the water decreasing her interest in bfing - I would just give her some water with or shortly after her meals and you should be ok.
Khalam's mama is definitely right about avoiding bananas. In fact, everything in the BRAT diet recommended for diarrhea (bananas, rice, applesauce, toast) should be avoided if you're having problems with constipation. All of those things can be really binding and just make constipation worse.
hth