bottles

Brooke
I need some ideas!!! 
A little background, my daughter is 8 months tomorrow, she has been bottled fed with breast milk since day one because she had low muscle tone. Randomly around 3 months I thought I'd try breastfeeding her, well she decided to latch and has done really well! 
The issue, all of a sudden she doesn't want her bottle (same brand that she's always had). I've tried different flow nipples to see if that was her problem. She got a cold and was congested, so thought that would be another issue, BUT, she will nurse just fine like she's not even congested.
Idk what to do now... any recommendations?