Mine has 8oz of hungry baby milk at 7pm bedtime and he wakes up at 2am and 4am for feeds, when I breast fed him his bedtime feed he'd sleep right thru lol!! I only started topping him up with the formula cos I wasnt producing enough for a growth spurt and we've just stuck with it but its not helped his sleeping!!
Id say it sounds like a growth spurt and I'd just go with it and give her as much milk as she wakes up for, I wouldn't try and give her food this young but that's just my personal opinion you know your baby best