I'm starting to realize that my mother will need to live with me for a while

My mother lives with me and my girlfriend now. The plans my girlfriend and I had before my mother moved in was to set things up so that she, my girlfriend, can finish college. Then she'll have better job opportunities and then we could be more financially secure--in time.

Now my mother lives with us because she's unable to find work OR at least it's very difficult as she doesn't have marketable skills and is not in great physical condition. The only saving grace is that my mother will get social security in about three years. However these are the three years my girlfriend wanted to finish school. Why does that matter? Our goal was to move in a very cheap living situation so that we can live off of my income--since my partner will be a full time student. Now it's unclear what to do.

My goal is to earn more money in a year so that I can find an apartment for my mother (a room) but that's still an uphill battle.

I've posted here before so some of you know the story already. My mother is looking for work. She has an interview tomorrow as a live-in caregiver. It's just that I really don't know how to take care of my mother while also trying to help my girlfriend accomplish her goal of finishing school. If only this could've happened when we were 45 years old. I think we could better handle it.