Sometimes those closet to someone can't get thru to people like this -- but have you told her about YT?? Send her here - tell her there are lots of breeders on here, people she could talk with, perhaps ask questions of, so she doesn't loose another puppy.
Turn this in to a positive - I'm sure there are than enough members on YT that would set her straight!
That way you're not the bad guy/neighbor who has their nose in her business