I want to marry my girlfriend however her children receive survivor benifits. It appears that if she gets remarried, her children will no longer be able to receive these benifits. Is that true? If so would we be able to have a domestic partnership or is there another union that won’t affect those benifits for the babies? We are both 40 years old.
No, that's not true. The marital status of a child's parent has no bearing on the child's eligibility for Social Security benefits (https://www.ssa.gov/OP_Home/handbook/handbook.04/handbook-0410.html).