Born in Yorkshire, Sammy began her career at the age of seven in pantomime at the Grand Theatre, Leeds. At the age of twelve she then trained at the Royal Ballet School and later went on to study at the Guildhall School of Music and Drama. 

Aged seventeen she joined the West End cast of the original production of '42nd Street' at Drury Lane Theatre, London. Her performing career continued in the West End for 15 years in shows such as 'Me and my Girl', 'Some Like It Hot','My Fair Lady', West Side Story', 'Seven Brides For Seven Brothers','Carousel', 'Sweet Charity','Singing In The Rain and 'Beauty and the Beast'.