Marriage Based i-485

I am helping someone to fill his petition. The petioner can work because he is on a F-1. The wife won't make more than 21K and is her first year working. She already has a achild from a previous relationship and is currently pregnant. They are 19 and 22 yo. No joint sponsor. Do they have any chance with her no reaching the minimun and no joint sponsor? Any suggestions? No money for an attorney either.