Yvonne Furneaux, Kate O'Mara, and Debra Paget:
Yvonne was in Federico Fellini's La Dolce vita and Roman Polanski's Repulsion, but she was never in an Elvis movie. She appeared with Peter Cushing and Christopher Lee in the 1959 Hammer film The Mummy.
Kate O'Mara was in the TV shows Danger Man, The Saint, The Avengers, and Doctor Who, but she was never in an Elvis movie. She appeared with Peter Cushing in the 1970 Hammer horror film The Vampire Lovers.
Debra Paget was in the Roger Corman films Tales of Terror and The Haunted Palace with Vincent Price, plus she was in the Elvis film Love Me Tender. A clip of her from The Haunted Palace appeared with Peter Cushing in the 1974 horror film Madhouse. (And she had the best legs.)
In La Dolce vita, hardly anyone noticed Yvonne, because they were all watching Anita Ekberg (a blonde). In Repulsion, hardly anyone noticed Yvonne, because they were all watching Catherine Deneuve (a great blonde).
In The Vampire Lovers (a fascinating film), hardly anyone noticed Kate, because they were all watching Ingrid Pitt and Madeline Smith.
In Love Me Tender, everyone (even Elvis) noticed Debra Paget.
(Peter Cushing had a great life!)