2 almost under 2

My daughter will be 26 months old when baby comes how did you guys manage? I probably wont have anyone to really help me lol & I've been trying to get my daughter ready for when baby comes by practicing with baby doll but she still says mom up & mom play when I'm "feeding the baby". After having baby have any of you sat on the floor? Cause alot of playing with her will involve that & I'm worried about the first couple wks after having baby 🥴 cause with my daughter it hurt to even sit on couch lol. Any tips you guys have or advice? Tyia 🙂