Bipolar ex gf texted me after 4 months, help?

I'm sure she misses you and at the very least DID love you but you need to let this fish swim away. If she's not on meds you're in for a roller coaster of a life and that's just not healthy for ANYONE including her. You can't take on the responsibility of parenting her so let her learn a few lessons the hard way. Eventually she will settle down and start taking meds. In the mean time, you should find a girl with a little more stability to make you happy.