It's a huge and honorable step that you're concerned about her anxiety and willing to learn more in order to understand what she's going through.
I think it comes down to her wanting to help herself before anything can get better. But people with debilitating anxiety sometimes cannot see that, therefore, they need that extra push to get them to seek help. It certainly sounds like her meds aren't working at all. Is there a reason her doctor isn't changing her meds? If so, perhaps she should see a different doctor, one who will listen to her concerns.
You said you don't want to be pushy, but I think that's what she needs if she won't seek help on her own accord. Let her know how the anxiety is also affecting you. Perhaps when she realizes that she'll want to get help for herself.
I won't comment regarding the situation and how it affects your son. I don't have children of my own and probably wouldn't be of much help.