First Time Momma Concerns

my little lady was born on 7/31 weighing 6lbs7oz and is now 5lb13oz- just at her 10% weight loss. im breastfeeding and i’m worried that shes not getting enough since shes lost so much. when i hand express i get colostrum so i know it’s there... how do i know that when shes sucking that shes getting it and swallowing? shes been pooping multiple times and its turning green (which im told is a good sign) but i feel like she isnt peeing much (or maybe im just not noticing because she also pooped??). we get to go home tomorrow and i plan to start pumping. i know it’ll get easier when my milk comes in but i’m just so worried that shes not getting enough. she sleeps well and doesnt act starving but i’m a first timer and so full of concerns.