2 month old baby drinks milk every hour.having less breast milk so using formula.she drinks 2.5 oz at a time & she stops when she is full.overfeeding?

Maybe/maybe not: Children modulate their own input and rarely overeat or undereat on their own volition. There are standard growth curves you could check your child's growth against. Talk to your child's doc.

Feeding : Nursing every hour is not unusual and hard to overfeed with nursing. 2.5 ounces of formula an hour seems to much for this age. But to know for sure you need to see the growth chart for her