Ralph is right. $50,000 sounds like a lot of money. But it's easy to fritter away. If your mother is secretive about her money and doesn't want you to know where it is, enlist a friend she respects to help her though this.
My parents were very secretive. I had no idea how much they had or where it was. But my mom was extremely organized. It only took a few months to settle their estate. My husband was not organized. He also came from a Depression Era background. He not only spread his money in several "nests" (i.e. accounts) his had the nests on several different "farms" (institutions). It took me five years to find them all.
Good luck. Trust me, it's worth the effort.