Like WK I'm afraid I don't have much good news either.
I have Bipolar 1 so my form of Bipolar can be quite severe at time. So I'll try and offer some insight from a different perspective.
For this post I'll assume a diagnosis has been made.
I was undiagnosed for around a decade, during that time I diagnosed with various other conditions, until a competent psych finally diagnosed me. I also refused meds.
It was suspected by family members however since I was around 15 that I was Bipolar.
About a decade ago I was diagnosed and medicated. However I have or should say had a stubbornness for medication. I took a/d to control the depressive lows, but would quite often stop my mood stabilisers due to weight gain, so my manic stages would still come.
2 or 3 years ago, everything in my life came to head. I was manic irritable and was becoming psychotic. I had also learnt a lot mental health due to studies and qualifications which helped me immensely to notice symptoms and learn more in general about my illness.
So I was medicated, still not keen on the idea 30kg of extra weight sees to that, but is better than the alternative. I still have bad days, but I think we all do.
You mentioned you spoke to her treating psych, no doubt you had good intentions and were concerned, is it possible that she seem that as a betrayal? Personally in those instances for me that would be how I'd see it, and the anger for perceived hurt and betrayal with Bipolar can cause rifts and even relationship issues.
I also can't be told I need help, I will lash out with that, I need to recognise it for myself, however as time has progressed people have learnt ways to get me to recognise symptoms they notice so I realise I'm not quite as stable.
As for talking to her treating psych, if you get the chance again, instead of talking to them, ask her if you can talk to them because you are concerned for her and just want to help.
However I get things are uncertain for you at the moment regarding the r/ship. So much of what I said may be moot anyway.
Sorry I can't be more help, I wish you all the best.