She appears at 8:55 of the video: Watch a much younger Kathryn Crosby singing: And here is a recent performance by Kathryn Crosby.
The beauty has found much greater success by starring in the likes of The Darling Buds of May, The Mask of Zorro and Entrapment.
It was a fine day to take a stroll and as Bing Crosby meandered along he spotted Kathryn Grant, a young actress who hadn't even been born.