Welcome to PC

I'm sorry that you are in this situation. Since no one here is an expert and can't diagnose there is no way to know if she has Bipolar or any other mental illness of course. Most Doctors won't even make the diagnosis at the first or even many visits later, that doesn't mean they won't try out some medications meanwhile.

There is really no way to force someone in to getting help if they don't want it.. You can just try and be kind about it, You don't want her to feel like shes being ganged up on.

I hope she agrees to reach out for help.

Good Luck