Was Shelley Winters an Olympic swimmer?

Shelley Winters ACTED as an Olympic swimmer in the movie 'The Poseidon Adventure'

...Interesting characters with a range of backgrounds add interest to the story. These include a priest who believes that God supports those who make their own luck, a coarse cop (Borgnine) and his ex-hooker wife (Stevens), and an ex Olympic swimmer (Winters). Winters did her own swimming stunts and had to learn how some one of her class would actually swim.
http://www.people.virginia.edu/~jnd/a-z/p.htm#PoseidonAdventure