There is a little known program barely advertised by the Social Security Administration that can help certain people qualify for Social Security Disability even if they don't have enough work history to qualify.  It is called the Adult Child Disability program.  Here is a quote decribing the program on a Social Security Website

An adult disabled before age 22 may be eligible for child’s benefits if a parent is deceased or receiving retirement or disability benefits. We consider this a child’s benefit because it is paid on a parent’s Social Security earnings record. We make the disability decision using the disability rules for adults. The adult child including an adopted child or, in some cases, a stepchild, grandchild, or stepgrandchild—must be unmarried, age 18 or older, and have a disability that started before age 22.

So I know this sounds a little weird, but if a person is disabled prior to age 22, then they may qualify for SSD if and when one of their parents dies, begins receiving Social Security Disability, or begins receiving Social Security retirement.  And it doesn't matter when this happens.  For example, if you are found to have become disabled at age 19 and you were 48 years old when your parent began receiving Social Security retirement benefits, you could be eligible for SSD under this program.  Word to the wise - if you might some day be eligible for this program, keep track of your medical information - it can be hard to prove you were disabled many years in the past.  There might also be some other restrictions.  This is a somewhat complicated program, so talk to Social Security or a Social Security lawyer.  Also, more information can be found here.