Hi Trish
There is some fantastic advice posted here. The only thing I can think of to add is:-
Without being able to see what is happening it sounds to me that your baby has very little stored energy. This is not unusual for a baby that has had jaundice, and even more so if dehydrated. Breastfeeding does take a bit of work for the baby o if energy reserves are low they will often feed for a short time then just fall asleep. I would suggest that if you feed your baby with EBM from a cup or spoon she would not have to work as hard and then hopefully build up her energy reserves. I would do this for at least 3 feeds and perhaps even more. Try to keep the close skin to skin contact.