My mom is a 56 year old widow. Is she eligible to receive her deceased husbands social security checks?

In order to qualify for SSI disability benefits, your mom has to have a severe physical or mental impairment that prevents her from performing work that exists in significant numbers. That she has no work history is not by itself enough. Can she stand for or walk six hours out of an eight-hour workday? Can she frequently lift and carry up to 20 pounds and occasionally lift and carry up to 50 pounds during an eight-hour workday? If she can do these things, she's probably not be disabled. If she cannot do these things because of some impairment or combination of impairments, Social Security may find her disabled and eligible for SSI disablity benefits, based on her advanced age and lack of work history.