If she doesn't have a green card, she will need EAD. Without one or the other, she cannot legally work. If she has one or the other, it's a good idea to go right to the Social Security Office and get a new social security card with the "Now valid for Work" statement removed. Technically, one can legally work before having that statment removed from the card, but many employers will object if it's there and require that you get a clean SSN card. The SSA won't remove it until she has a green card. It's basically meaningless, since she DOES need DHS authorization, but some companies don't like to see it none-the-less.