Having said that, your GF is an adult and is responsible for herself including getting a job and finding a way to make ends meet.
I agree with I_Am_The_Fire. Sometimes I felt codependent guilt and other times my exuBPDw made me feel guilty from
FOG, does the guilt come from within or is she making you feel guilty from the things that she says?
Either way, maybe try analyzing where the guilt is coming from, as a codependent, I naturally felt like I had to fix things for my exuBPD things that she really should be doing on her own. You can learn about FOG, spot it and understand why a pwBPD illicit guilty feelings, you can learn to depersonalize it.
My advice is don't rescue and get a court order for maintenance and custody, get it in black and white, you don't want he said she said in court.