Sippy Cup???

Anyone started thier little one on a sippy cup. My little one prefers my breast and won't take bottles. I just ordered the tommy tippee transitional sippy cup with easy to hold handles. I'm hoping I can just give it to her with breast milk and let her play with it and explore....it will eventually end up in her mouth because thats where everything goes. Maybe it will work??? Anyone have a babe who skipped bottles went right to sippy cups?? I have a Christmas party I'd like to go to but don't want to take her with me. Really need a soloution to bottle feeding!