I consider anything before 6 am a nightwaking. So 5 am, feed and put back to bed. If you can get her to sleep until 7 or so, that's wonderful. It sounds like she needs to eat about every 3 hours, but if every now and then she wants to go longer until a feed, it's okay. I did 2.75 hrs around that age. I think this is what we did until 4 months:
feed at 8, 10:45, 1:15, 4:30, 7, put to bed by 8, wake and feed at 10 (she wouldn't eat asleep like a normal df so we had to completely wake her, she'd eat and go back to sleep all night). That's six feedings. At that time I was bf, so I can't give you an oz count, but that would be roughly 24-30 oz if she took 4-6 oz per bottle. You didn't mention (I don't think) if you give a df or have tried giving a df.
I don't think you can think of an 8 hr stretch at night the same way you think of length between feeds during the day. It's probably part of our neurological settings.
As far as her short naps, try putting her down for her first nap within an hour of waking. So, if she wakes back up at 7, put her back down around 8, then feed her around 10. I may be wrong, but that worked for me. You don't want her to get so tired that she can't rest all day. If she nodds off while eating, do the best you can to wake her. If she doesn't take her full feed, I would guess that she's using that to fall asleep, which is what you don't want. I think once she gets some rest, she's gonna straighten right out. It's all just a cycle, one thing affects the next. You're doing great!