How's your friend going?
Calling the ABA would be a great idea, if she's up for it. It is so hard to go and get help, isn't it? It's one of my greatest regrets from early motherhood - not seeking out more help. It's out there if you'll just go and find it.
Would she go to a local meeting of the ABA if a good friend went along with her perhaps...? Once she's met her local counsellors she might find it a lot easier to seek help.

4-hourly feeds for a newborn sounds very wrong to me.... 2-hourly would be closer to the mark at that age - and especially if weight gains are a worry.
I'm not sure what the go is with the shield - you'll have to ask about that. Was the nipple damaged? Or maybe they told her to use it as it's flat/inverted or something...?

Hope she and her baby are doing well.