You should comfort and support her during this tough time.

If your wife doesn't have a job,IVY college will give your child financial aid base on your family income, but may have to wait until next year.

I think it might be a good idea, you stay, and she leaves and try to find a new job. 

Don't blame your wife, it is not easy for her to work and take care of four kids."God closes a door, will open another window".