[3] Born as Isobel Shivas, she acquired the name Quita due to her mother singing Marquita while she was young,[3] she attended Aberdeen High School for Girls but her athletic talent was developed while studying at the University of Aberdeen, as well as athletics she also played hockey and golf.

In 1947 she competed in the 200 yards event at the 1947 International University Games in Paris, and came home with the silver medal.

After graduating in 1951, Shivas moved to London to work at Hammersmith Hospital and continued her running by joining the Spartan Ladies Athletics Club.

The following year she was selected to compete in the 100 metres at the 1952 Summer Olympics held in Helsinki, Finland, where she ran a time of 12.5 seconds and finished third in her heat behind Shirley Strickland and Vera Krepkina.

[3] After retiring she qualified as an anaesthetist and in the 1960s she married Stuart Barber and had a daughter Judith, and eventually settled down in Newstead, Scottish Borders, where she lived for the rest of her life.