J.S.
Your mom and sister are going to have to talk to lawyers that handle adoptions specifically. Then your mom should look into the Department of Women's Services or the equivalent of it in Texas, or start with the Department of Housing and Development. They're both State departments and they can point her in the right direction. Department of Women's Services is more geared towards helping women in your mother's position though.
EDIT: There are assistance programs within these departments that don't involve "government handouts" as some people are so loathe to give to even deserving people. These departments are RESOURCES to help people find affordable housing, affordable lawyers, explain laws and procedures, explain what special circumstances they may qualify for and can take advantage of, all without having to take a government check. My mother worked for the Dept of Women's and Children's Services in CT for several years and found it to be VERY rewarding work. They're a DSS. DSS isn't just a money pit, but they perform, well, social services. She currently works for the state prosecutor in Housing and Development, but that's a HUGE department and they have invaluable resources for people that you would never think of.
These are programs that everyone can take advantage of, not just the downtrodden. But people don't know about them, or they have the wrong idea about them. People like your mom and sister especially need them. If nothing else, they can get help with finding a good lawyer for the Adoption Reversal through Dept of Women's Services which is a division of the Department of Social Services (DSS). But they can also help your mom not only find housing, but a job that's suited to her MS... including a job she's qualified to do at home if necessary with a legitimate employer.