You do want to have her up around 24 ozs minimum at this age... I would start by reducing solids a bit to see if she becomes more hungry for milk... That is a lot of solids for her age... generally, babies should start with a single offering of solids at 6 months, so to be on three offerings at this age is likely too much. Many babies love the variety that solids offer in terms of taste etc, but nutritionally, this is a bad idea.
I would start by cutting solids way back for a few days to see if this is what is happening with her.
So, bottle at wakeup, offer solids an hour later.
Then, formula only for the rest of the day (at her age, I would offer 8 ozs every 4 hrs).
See how she does for a few days so we can get that milk back up.