She got way more than she paid in.
Why does that matter? If she was allowed to opt out of the system, then asked for it in her later years when she realized she needed it, then you'd have a point. But she participated in the system the same as anyone who agreed with it. To not partake in the benefits after you've paid into it makes zero sense.
Everybody except the rich does.
First, that's not necessarily true. My father died this year at 65 years old. Do you think he got more than he paid in?
Second, why is it justifiable to take from the rich? It is their property, so if they're not benefiting from it, how do you justify taking it from them?
I actually am in favor of social security, but let's be honest and use valid arguments, shall we? First, a society that allows people who can't take care of themselves to suffer is a very cruel society, and not one I'd want to be a part of. Second, the rich do benefit from social programs, because a large number of homeless individuals in the society they live in isn't conducive to business and it will hurt their bottom line. Example: I have no children, but I bought a house near a place with good schools. My property taxes pay for that school, and although I don't benefit from the school directly, my property value appreciates at a greater rate as a result of it, giving me an indirect monetary benefit.