How do I know if she’s getting enough?

We have started transitioning my LO to bottles of breast milk for when she starts daycare and we have been giving her 4 oz every 2ish hours.

She’s 11 weeks. How do i know that that is enough for her? She sucks on her hands a lot during the day so I can’t use that as a hunger cue. Would she be super fussy and uncomfortable if she was still hungry?