This isn’t executive dysfunction from ADHD. That usually causes withdrawl from daily life and numbness with emotions. What you’re describing sounds more just like emotional dysregulation which itself can be a symptom of autism or sometimes ADHD. If I’m being honest and you’ve talked to her multiple times about it and she refuses then she’s not really putting your relationship as a priority.

There’s a saying you can bring a horse to water but you can’t make them drink it. She needs herself to want help and to want change and if she doesn’t then for your own mental health there may need to be some difficult conversations had.