Split between the brother and sister, it wouldn't last more than two years.
Even 50 grand is a good size windfall. I daresay half the population could be convinced to let grandma, or mom, or dad, or brother or sister, "go to Jesus" a little sooner. "Better than the money going to the hospital, eh?"
And so has human nature been since time immemorial.
Just a small %, but enough. Study the middle ages, for example - family slaughtering family, including children, to inherit monies and/or titles.
The Native Americans did not allow inheritance. They saw it as the danger it was. Lot of wisdom in some of the old Native American ways.
In the meantime, I'm glad I'm not rich. I don't have to worry about anyone waiting for me - or pushing me! - to die...well, at least not for material wealth ...