baby not drinking!

My 8 1/2 month old is eating solids and now she WILL NOT take her formula. If she does she may only take 1-3 oz, I'm really worried cause I know babies need formula at this age...she isn't fussy or anything she just will only take a bit and than just stop! She takes her solids just fine, it's just her formula she barely takes anymore. I know we can always go to her pediatrician, but we're military so she has many different kinds and they always give us different opinions. I just wanna know if anyone went through this with there own LO and how'd you handle it.