I remember a few years ago I was in a similar situation. I had four little girls and a mortgage and I had to quit my job because my family and I were off to bible college.
I wanted to sell my house before I quit my job cos that was logical. However I was forced to resign so someone else could be appointed before I sold my house.
The point of my rambling is this. I struggled with the decision. I walked around school (I was a teacher) with my letter of resignmation in my poscke for almost 2 weeks before I had the courage to hand it in. The day I handed it in I floated out of work that day on a cloud. It was so releasing.
Sometimes we just have to make a decision and do it. Of course we need to be responsible as well. My kids are all grown up now. It happened so quick so .... DO ALL you can to make these years memorable for your daughter. You only get one shot at it and she will cherish her memories of you being there for her more than having the latest stuff.
You are doing the greatest job of all ..... MUM
All the best .. Colin