V.G.
I DISAGREE with Shandra and Cathy. Baby cereal doesn't need to be mixed in with your breastmilk in order to "satisfy" your little one- she gets everything she needs from your milk (of course starting to offer solids is ok, but do it on your own timetable).
I think its a phase. My son did the same thing, and it lasted for about two weeks I think. Each time he would do it I would say "ow, that hurt momma" and he did eventually stop, but I think I also would break his latch with my finger right before I thought he was done to avoid that pulling for awhile.
My son thought it was funny getting a response (usually an "OW!") from me from doing it, so maybe breaking the latch JUST before she's done will get her to forget about it. :)
Good luck! :)