D.D.
This is common especially in reflux babies. Milk is a natural antacid, so when a reflux baby starts to have some pain, she wants to eat because it's soothing. It is especially common at night, because laying down aggravates the reflux, so she wants to eat more often at night to keep soothing the reflux pain.
Ironically, the solution isn't to put more in the bottle. Too much fomula in the tummy leads to even more reflux, which causes more pain, which makes her want to eat again to sooth the pain. I would actually suggest that you don't feed her more than 4 oz at a time, and accept that wanting to eat frequently is going to be common until she grows out of the reflux.
Sorry that is not what you want to hear. I hope you have someone to help with nighttime feedings, because getting a reflux baby through the night is exhausting.