RFE sent help!

Im an f1 student who married a citizen. My wife is unemployed so my sister will be sponsoring me. I only filled out an i864 for my sister. The RFE said I need to fill one out for my wife too but this is what they asked for "• Submit a complete copy of the petitioning sponsor's Federal income tax return, including all supporting tax documents (W-2s, 1099s, Form 2555, and tax schedules) filed with the return, for the most recent tax year". My wife hasn't worked in 3 years, hence why my sister is the joint sponsor and makes enough money to sponsor me. My wife's last tax filing was 3 years ago. Do I send that along with the i864 for my wife? Please help!