Waking baby to feed?

Ak
I'm having a really hard time getting baby to wake up and feed. She would rather sleep. 
When we were in the hospital at night they would give her formula because she would take it and had it fast with the Bottle. My milk hasn't come in and I'm worried she's not getting enough but she basically gets lazy about it and doesn't want to do the work to get the colostrum out. Any tips?
Unswaddling and undressing her doesn't work. And neither does changing ber diaper