Sleep.. I need tips!

Ok... so my daughter is 15 weeks. Since she was about 6 weeks this is her routine ...

8:30/9 pm: swaddle, bottle, falls asleep in bassinet

Sleeps until 1:30/2 am. We give a bottle in bassinet and she falls right back asleep (which is amazing).

3am-on: restless, whines, makes noises, cries... she usually falls back asleep if we put her paci back in or give a bottle (if she’s crying a lot) but doesn’t stay asleep. This goes on until we finally get up around 7 am.

So, my question is.. is she sleeping light because she’s hungry? What else can we do to help her sleep in longer stretches after 2/3ish AM? I keep thinking the older she gets the longer she will go between bottles but last night we gave her a bottle at 1:30, 3, 4:30, 5:30, 7 and 8:15.. I can’t keep this up and I’m sooo tired from it!!