D.P.
My daughter was the same way. I stayed at home for 6 months and then went back to work. I pumped and tried to have my Dad (who takes care of her) give her a bottle and was lucky if she took 2 sips out of it. I went to a sippy cup and it worked. The pediatrician said it was fine as long as she took fluids. B/c they state around that age any water should be given by sippy cup anyway. As time went on she got better at it.
Girls are stubborn and only want what they want. I would suggest a sippy cup or sippy/nipple cup. See what happens.