My friend gets SSI and she met someone who wants to marry her, what would happen to her SSI if they marry and would she be able to get spousal SS when he retires. Thank you
If by SSI you are referring to Supplemental Security Income (SSI), then getting married could adversely impact your friend's benefits. SSI is a needs based benefit, and if you're married and living with your spouse then their income and resources are considered when determining whether or not you meet the financial hardship requirements for eligibility.
If, however, your friend is receiving Social Security benefits then those benefits could only be affected by marriage If she receives benefits based on someone else's work record, such as an ex-spouse. Your friend might be able to receive spousal benefits on her new husband's record if she's at least age 62, but she'd probably need to be married for at least a year in order to qualify (https://www.ssa.gov/OP_Home/handbook/handbook.03/handbook-0305.html). And, she could only qualify for spousal benefits if her new husband is drawing his benefits.