I was just looking at my notes from when Jack was 4 months old, and his routine was this--
7am- wake, BF
8.15- 10 nap
10- bf
11.15-1 nap
1-bf
2.15-4 nap
4-bf
5.30- 20-30 min catnap
6 bf(small feed)
7-bf
asleep by 7.30
He was waking sometime between 12-3 to eat, sometimes twice a night, sometimes once.
So I figure he was getting around 7 feedings a day.
I am thinking that she is skipping some daytime feeds because she is trying to make up for night time sleep with those LONG naps. I would try to shorten the naps, lengthen the night time sleep, and feed every 3 hours. (Easier said than done, I know! You will probably have to do this gradually if she is touchy about her sleep.)
I've got to get to bed, but I will try to check back tomorrow.