I see nothing absolutely wrong with a man helping his wife to do the homework.
Most people in Africa have this notion that the work of house belongs to the woman, a woman's office is in the kitchen and the man just supplies the financial needs. It doesn't have to be this way, as a man there is nothing wrong to help your woman out with the house works.
Am yet to get married, I don't even leave the house works alone to my girlfriend when she comes around, staying together helping her in the kitchen is quite fun for me, we chit chat as we Cook. This makes it less a work for her, I also join her in washing.
What is actually wrong is women or Ladies taking the help for granted,they now assigning duties for the man. I wouldn't do it, but at will i wouldn't let you do it alone.
I often help my wife do homework. and I do not admire that a husband helps his wife's work is a mistake. because to help a wife depends on conditions. for example, a wife is sick, so a husband should do homework. and the reason I help my wife do homework is because we already have children. of course my wife's work is piling up because she has to take care of children.