She's not "in the Hall," but it's understandable that people get confused about this.
Only the 260 people elected as members are "in the Hall." There are exhibits, both temporary and permanent,
about countless other people. There's a display about the Abbot and Costello "Who's On First?" routine, for example, but they aren't "in the Hall."
Their entry in the Hall of Fame FAQ serves as an example about how many people get confused about what it means to be in the Hall.
There are also players whose effects are in the Hall simply because they were involved in memorable moments. Aaron Boone is never going in the Hall, but they probably have the bat he used to hit the home run that ended the 2003 ALCS.
Think of it this way: The full name of the institution in Cooperstown, N.Y., is the
National Baseball Hall of Fame and Museum. It's referred to as "the Hall of Fame" by everyone as shorthand, but once you realize that the Hall of Fame and the Museum are two separate components of one institution, it all makes sense.