Any guidance ?

I’m a FTM and am breastfeeding . Her latch is good and she is getting milk, my milk is coming in so there’s more of it than the last 2 days . But is it normal for her to eat sometimes for only 5 minutes and fall asleep ? She’ll have maybe one decent length feed and the rest are short like that and knock her out, normal? She has her first checkup tomorrow so I’ll ask then but I’m just nervous