Feeding and growing last step before home

My daughter was born at 31+5 weeks in September 3rd. She’s now 35 weeks and she started trying to bottle/breastfeed about a week and a half ago. She takes anywhere from nothing to 20 ml but it varies so drastically and she doesn’t take a lot most of the time. My question is how long did it take your baby to learn to feed? I just want her to eat so we can get out of the NICU. She’s almost 5 pounds so her weight is fine I just feel like she’s relying on the NG tube and maybe they should remove it so she will be hungry.