That is pushing *your* agenda onto her. It is never a good idea to coerce someone to do something that they fear doing. She has her reasons and you ought to respect that.

Your fiancee(?) is not a diagnosis and not all "bipolar people" or "bipolar people issues" are the same.

The best support you could offer her is guide her to mental health support, for her sake not for yours. Only she can work on her issues, with support - not by making her do what you want.