I'd personally just look for her hunger cues and feed on demand...sometimes my boy took a full feed other times not but I fed him when he was hungry. My HV also said that if they want 1 or 2 oz give them that as they quite often cluster feed or just want a bit and then give them more when they're ready. It's okay if she doesn't always take a full feed 🙃
Depends how much LO is drinking in one feed? 1 oz roughly 1hr. Are you breast or bottle feeding? If breast feeding try tickling/ rubbing feet when LO starts to fall asleep to wake them up to finish the feed.
Let the baby take the lead. They will want a feed when they’re hungry, if they’re quite content then don’t try to force feed. If they’re tired they’ll let you know. Listen and look for signs. They’ll let you know. They’re human too, do you eat exactly at 12:00pm? Do you fall asleep as soon as the clock hits 9:00pm? No, so don’t expect that baby will want to feed exactly every 3 hours apart. Try to relax and just enjoy the moment. As long as baby is gaining weight and happy, then you should be happy. And try to nap when they’re down for a nap. A bit of sleep should make you worry less.
Feed the baby when they’re hungry not according to the clock. It’s biologically very normal for a baby to feed little and often. Nature didn’t design for them to have big feeds every 3-4 hours that’s just what society pushes for convenience x