She gave the rights to her only grandchild, Mathew Prichard. He was nine years old at the time. She had no idea what a gift she was giving him.
He made a lot of money from that but he wound up being the sole inheritor of her entire estate and has made millions of pounds over the years from royalties.
While I'm in a correcting mode, I can't believe that article said The Mousetrap has never been done in New York. As has been pointed out already here, it ran for about five months off-Broadway in 1960.
