Along the lines of what Jim posted above they could check out the Association of Gospal Rescue Missions at
AGRM - Home Many locations offer long-term rehab 90+ days at no charge. I used to volunteer at my local location and it's a good program. However, they would be in separate men's and women's programs.
If you choose to co-sign on anything, go into it seeing it as a gift that you will be solely financially responsible for...along with any damages that may occur.