My 3rd one did the exact same thing! His older brothers never had any issues with ear infections, sickness, anything. They were all breastfed for over a year, etc. After 2 ruptured eardrums, we ended up getting ear tubes. They were magic! Now, I am not saying you need to rush your child into surgery, but that is some thing you may want to ask your Dr. about.
As others have said, taker her to an ENT (ask your pedi for a reference if you need). It is really important that the infections get cleared up. Her permanent hearing and speech will be affected if she constantly has ear infections at this age- it is a major developmental age for speech and hearing. They both affect each other. She can't speak properly if she can't hear properly. The ENT will give her an exam and they usually have an audiologist in their office and she will be seen by them to make sure she is still hearing properly.
Also, ear issues are notorious with dairy allergies. Cut the milk, cheese, yogurt, etc out of her and your diet (since you still BF) and see what happens. You will only have to do it for a week before you know... probably sooner.
Good Luck!