Dehydration is a big concern. It doesn't take much for a little one to get dehydrated, so keep pushing liquids, but steer clear of juice which can make diarrhear worse. My 2 year old son doesn't like Pedialyte either, but the Gerber brand (the name escapes me) was recommended by some other moms I know. Stick with the B.R.A.T. diet as mentioned previously: bananas, rice, applesauce, toast.
Start counting how many wet diapers she has per day. I think she should be having at least 4. If she's not peeing that much, call the pediatrician or take her to the ER immediately.
There is a nasty stomach bug going around, could that be what's causing her diarrhea? Or is it perhaps a food intolerance? (Rice and corn both give my son diarrhea.)
As I find myself telling lots of new moms, doctors are the experts in their respective fields, but you are the expert on your baby. Follow your gut.
Good luck!