Originally Posted by The Incredible Hulk
She'd be like 100 years old now. Steve's been in cryo-stasis for 70 years. I think it'd be a real stretch to have her still alive. Maybe just doing a scene of him visiting her grave would be more realistic. You could sort of get into the Superman type territory where the hero has to deal with everyone around him dying long before he does.
This is sort of the problem with Cap's origin. As time marches on, you've got to have him frozen for a longer period of time which means less and less people who knew him would realistically still be around. Sooner or later Cap is going to become like Demolition Man origin wise.
My great grandma, who died this week, lived to be 94. Peggy was probably fairly young, so her being over 90 still works.