That makes no sense at all. The future is an unwritten book and you don't know where life will take you. Having an advanced degree will always give you more and better options.
You also don't know if she will be in your life forever and you need to do what's in your own best interest too.
Well, that works both ways. If an undertaking like this pushes her away, it could end up costing more than it's worth. They have children together, you know. She needs to be on board.