I usually my political opinion leans slightly to the right of the middle, but even I realize that you can't have things handed to you and succeed later in life.
If you want to help her, you have to let her fail before she can succeed. Failures can bring about quicker positive change than false success ever will. Either way, she will have to survive on her own later eventually.
She might as well realize that life and the world around her are not fair.
Suck up your pride and your wife's pride and let her fail for awhile. If she needs help, get someone to help her, don't just do it for her.
Nothing positive can come from proving that you can do High School level homework still.