does my wife have to fill out the form I-864 too, my wife income is not enough..
does not matter who else is sponsoring. Your wife has to be the primary sponsor since she is the petitioner.
Which means that i will have to print out 3 copies of I-864 for my wife, my wife mom, and her friends who are sponsoring.
You do not need 2 co-sponsors. Your wife and one co-sponsor only.
zicomania
You would be sending 3 I-864's. One from your wife, 2nd from your wife's mom, 3rd from her friend. Based on poverty level, try to look if your wife's mom's income is sufficient, then you would not be required to send I-864 from her friend.