Baby needs to nurse on demand, especially during the growth spurts that occur at 2-3 weeks, 6 weeks and 2 months. Baby can’t go 3 hours. Baby is screaming and attacking boobs because he’s hungry. Baby attacking boobs is what will increase milk supply for future growth spurts. Sleep deprivation is part of parenthood. I appreciate you trying to help but if she wants to breastfeed than she needs to buck up and feed the baby.