At this age you definitely want to try and make sure she's feeding from at least one side at least every 4 hours. Change her nappy or strip her down to wake her up. And don't panic! Soon she will get there and want to feed aaaaall the time :o
It is extra tough when they have been bottle fed as sucking from the breast is exhausting for them and can use up a lot of their energy. I had to top up DS2 for a while because he just wouldn't feed from me enough to keep his energy up. I was instructed to only let him feed for 10 minutes
and then give him the top up which I found ridiculous so what I did instead was I would let him sleep and then wake him up after 4 hours, change nappy, let him feed as much as he wanted and then give a small top up - up to about 30/50ml. I did this with paced feeding. In between the 4 hours, if he was happy to feed from me I'd let him feed as much as he wanted and only offer the top up at the 4 hour point. That seemed to help keep his blood sugars up enough for him to get the hang of feeding. I also found an hour's skin to skin/kangaroo care in the morning helped him fantastically (I probably would have done more but we were in hospital and it kept dislodging his monitor pads and I had to ask the nurses to redo them
)
Any spare moment I had during the day when he wasn't feeding and I wasn't showering/sleeping/eating/having visitors I'd try and sneak in a 10 minute pump on each side and keep that. If you were more dedicated than me to pumping you could have a 2/2 schedule where you feed every 4 hours and pump every 4 hours during the day with 2 hours' interval between each.
La Leche League says to get back to full breastfeeding do the three Keeps:
Keep the baby close (as much skin to skin, cuddles, smelling their lovely little head etc as poss)
Keep the baby fed (breastmilk or formula, it's not important)
Keep the milk flowing (feed directly or express, once every 4 hours as a minimum, 10 times in 24h also sounds like a good goal)
Once you've got feeding more established and your baby is less sleepy you can go back to feeding on demand. Think of it as just encouraging a few extra feeds rather than taking away her say so if it helps.