How to undo bad training?

Hello again, I have a 16 week old Patterdale-jack cross called Ripley who I can now stand(ish) for.

My partner is stuck using very, very outdated methods to train her when she does something bad (pinning, shouting, kinda hard nose taps, think along those lines) and I've told her it doesn't work and the methods to use instead. The issue is she won't listen since I haven't had a dog before and she's been around them her entire life, 4 lovely dogs who ended up having to go to trainers (shock horror -_-).

The issue is that Ripley was making progress with coming to her name and other basic commands, but since my partner has started this style of training Ripley has backtracked heaps. She doesn't listen, whines and will stand just out of reach and bark aggressively for hours. She doesn't trust treats anymore because they were used to bait her closer so she can be put in her crate.

How do I undo this? I am finally in a position to train her, I can at least stand up now at a hard push and I don't want to give up on Ripley.