Hi!
It seems like you still have your LO on a three hour routine. Have you thought about switching her to a four hour EASY routine? After babies are about 4 months old they can go for longer periods between feeds and sleep. I know that my DS feedings and sleep was so out of whack until I realised that this was his problem!
There's a sample of the 4/4 (four months/four hours) routine in Tracy's new book, The Baby Whisperer Solves All Your Problems. I think there's also a sample of the 4/4 EASY routine on the activity board.
HTH!
Hugs, Charlotte