Cathy Lee Crosby held Joe Theismann's hand on the ambulance ride from RFK Stadium to Arlington Hospital Monday night and stayed by his side through the long night. She was also with him through the day yesterday in his private double room as Theismann's fans inundated the hospital with flowers, balloons, get-well cards, candy and even some stuffed animals. Hospital officials don't know what they're going to do with all the gifts coming in for the Redskins quarterback as he recovers from his broken leg. One hospital spokesman said more than 50 baskets of flowers had been delivered and at least three bunches of balloons. All the gifts have been shown to Theismann, who was listed in fair condition late yesterday. Theismann has asked that in lieu of gifts and flowers, any donations should be made to the Children's Hospital Development Center. The Mouse That Moved

It's a big week in town for unusual celebrities -- Donald Duck, Mickey Mouse, Minnie Mouse, Goofy and the rest -- but what is not generally known is that the Disney characters are Teamsters. At least the people who dress up as the cartoon figures are members of the union. They're to be here for two weeks of various activities and had all been booked into the Vista International Hotel. But when Ron Richardson, secretary-treasurer of the Hotel and Restaurant Employees, Local 25, found out, he called the Disney people.

The Vista is a nonunion hor cancer. Back home in New York, he is also facing disbarment proceedings . . .

Entertainer Sammy Davis Jr. was released Monday from the Cedars-Sinai Medical Center in West Hollywood, Calif., where he underwent reconstructive hip surgery. Davis expects to be recuperating for several weeks . . .