I'm not entirely comfortable with your question because you say she's unwilling to change and I don't understand why you are asking this question. It's not clear to me if you are butting in inappropriately or being helpful to someone who wants your help.

If she doesn't want your help and it isn't somehow your responsibility, you should butt out.

But I'm replying based on your last paragraph here.

It might help her to start a private journal and write about what happens so she can pinpoint the exact problem. Once she knows exactly what is tripping her up, coaching or practice or just thinking through her options may help.

I'm a woman and I've had to do a fair amount of analyzing "What went wrong?" in interacting with other people, especially men, in professional settings. So I think it can get better, especially if the person in question puts in some time and effort to ID the exact issue or issues and then start brainstorming "How will I respond to that in the future?"