M.,
she sounds perfectly normal and she will lean out as she becomes more active. A good formula for how much she needs to eat to be nutritionally stable is this:
2.5 oz x body wt every 24 hours
2.5 X 15.2 = 38 oz per day. Now as she continues to grow she will of course need more and she will get alot of it as she begins to eat cereals etc in another month or 2.
To determine the amt per bottle just divide the 24 hour amount by the number of feedings per day.
So if she is taking a bottle she probably gets 5-6 feedings per day or from 5.6 to 6.4 oz each time she eats. Babies are like us, there is a delay from stomach to brain on feeling full. Like we need that 3rd slice of pizza Becauseeeeeee?(it just tastes good) So she may keep eating because she needs to suck, or it tastes good to her and she doesn't know she is full. These of course are guidelines to help you. None of us falls into seriously hard and fast rules.
I hope this is helpful, enjoy your baby and don't worry about all of the "rules". It seems they grow up just fine in spite of us.
K. @ The Nestingplace.