She probably needs to be wormed, and she also may need to be fed a different puppy food. She may be sensitive to something in what you're feeding her. If you are giving her inexpensive food, try switching to a higher quality brand with less fillers and grain products in it.
You need to take your puppy to the vet. Pooing 15 times a day is far from normal; meaning something is very wrong. Has she had any puppy shots yet?