G.B.
Yes, it could be reflux. There are many things you can do to relieve this. First talk to the doc. There are meds in addition to the gas drops the doc can give her. Our grandson took Reglan. It relaxed his tummy and he didn't have issues very often after that.
Giving many small feedings instead of one big bottle is the main thing too. Overfilling the tummy is the #1 reason for spitting up or puking after a bottle. Their tummy is very small.
Their tummy is about the size of their little hand/fist. That's how much they should be taking at most.
So small amounts every half hour or hour.
Sit them up to sleep, never lay them down flat. Sit them in a bouncy chair or car seat. This keeps them in the right angle so their food will stay in their tummy better. Car seats aren't very padded so try the bouncy seat for most of the time and during the night, be sure and put the bouncy seat inside the baby bed so if it flips over they are safe in the bed and be sure to fasten the safety straps in place.