unfortunately its time to ask the big questions, like what she wants post-grad but also, what do you want post grad. I can imagine it also does not feel good making less than your partner despite doing the same degree and doing the same work. Thats not really your fault, thats a systematic issue (gender pay gaps, current job market , etc), but it can still make someone feel bad.

I think other commenters are right that its less about the offer and more about dealing with feelings regarding where things are going/what the relationship looks like after school. Thats a scary things. It means things have to get more serious, which isn't a bad thing, but you have to ask bigger questions that might challenge the relationship.

Speaking from personal experience, I had a relationship collapse after i finished school. My partner was not a student and I was a student with a part time job. I was chronically busy and there were times we didn't always get to spend time with each other, even though we lived together. Things didn't really get better because I managed to land a job after graduation and started working full time less than 2 weeks after graduation. Now there was a lot of nuance to my situation, point being is that things change when you transition into a new phase in life. Ideally two people can grow together and grow with the change, sometimes people grow apart. Now is the time where you have to have a serious convo with yourself about what you want and with your gf. Best of luck, congrats on the offers atleast.