What Can I Do To Help My Friend With Undiagnosed Bipolar?

I need some advice regarding one of my closest friends. I am 100% she has undiagnosed & therefore untreated bipolar. It runs in her family (mother) and i’ve been seeing her display more and more behaviors that make me think she has it. It’s bad. I see her doing the same things I would be doing in a fit of mania, or depression, saying and doing some of the same things i would, which is Not good. It hurts me so bad to see her spiral, & every time i try to recommend her to get help, she comes up with an excuse as to why she wont (dont feel like it, too lazy, doesnt wanna prove her mom right, doesnt wanna do therapy, cant swallow pills). And everytime I offer a rebuttal she simply refuses. I really don’t know what to do bc it feels like a dead end but i know something bad will happen if it goes untreated for longer.