Mom has United Health Care with Secure Horizons and Dad's a veteran. What type of financial help can she get?

My mom worked her entire life, she has United health care by Secure Horizons AARP, she only owns a 30 year old mobile home that's worth nothing so taking her home isn't an option, I need some advice to see if she could get on Medcaid, I believe she is already on medicare.She is 83.Please send me any info that can help. she collects SSDI 1,200.00 per month to live, that's it!