[2] Following the death of Shirley Fry in 2021, Mortimer became the longest still surviving Wimbledon ladies singles champion.

Mortimer reached the quarterfinals of the US National Championships, then lost to second seed Doris Hart.

In 1961, she won the title, defeating top-seeded Sandra Reynolds 11–9, 6–3 in the semifinals and then Christine Truman in the final in three sets.

[4] In 1955, she was the first British woman since 1937 to win one of the Grand Slams when she defeated Dorothy Knode in the final of the French Championships.

[3] She won three times against Althea Gibson in her career, and she made her farewell in the Torquay Open Lawn Tennis Tournament of 1962, beating Ann Haydon-Jones in the final.

[5] Mortimer was appointed Member of the Order of the British Empire (MBE) for services to Lawn Tennis in the 1967 New Year Honours.