trying to live off their disability/SSI. The only help she has is Medicaid.

My sister is 43. She has always been considered a slow learner and could never hold down a job. She does not drink or do drugs ever. She has 2 severely autistic twin sons that are 22. She also has a daughter that will be 18 soon. She is the only full time care giver and they are trying to live off their disability/SSI. The only help she has is Medicaid. The 2 adult children receive disability. About $750 per month each. Since she doesn’t get heat, electric, rent, food assistance, she is afraid to apply in fear losing the disability/ssi they receive. The father of all 3 does not work. He is on disability. Due to the charges he may be facing for raping his own daughter he isn’t helping the family. My sister has filed for divorce. I am blessed and do not know how about assistance. No one answers the phone. How can I help her find out if there are additional assistance without affecting the 2 adult men’s money from Disability/SSI?