But she quickly learned the baseball great is a revered figure among collectors, and the most sought-after baseball card in history. And thanks to an unexpected donation, one of the century-old cards belongs to Muller and her order, the Baltimore-based School Sisters of Notre Dame.
The sisters are auctioning off the rare, century-old card. It was left to the School Sisters of Notre Dame by the brother of a deceased nun. The man had owned the card since 1936, and it was stowed away in a safe-deposit box.
It's in poor condition, but any Wagner card from the T206 series, produced between 1909 and 1911, is highly prized by collectors. The card is expected to fetch between $150,000 and $200,000.
Wagner, nicknamed "The Flying Dutchman," played for 21 seasons, 18 of them with the Pittsburgh Pirates. He compiled a .328 career batting average and was one of the five original inductees into baseball's Hall of Fame.
No one in the sports-memorabilia marketplace knew about the card because the nuns' benefactor had owned it since 1936.
The auction ends Nov. 4, and the highest bid was $60,000 as of Wednesday morning.
Sister Virginia Muller said proceeds from the sale will go to benefit the sisters' ministries in 35 countries.