Her best Grand Slam singles performance was reaching the semifinal of the 1963 U.S. Championships in which she lost to Margaret Court,[1] having beaten Billie-Jean Moffit King in the last 16.

[3] In that year, she won the West of England championships at Bristol by beating Sandra Reynolds in the second round and Renée Schuurman in the final.

In 1961 and 1963, she won the singles title at the Surrey Grass Court Championships in Surbiton, defeating Edda Buding and Darlene Hard in the respective finals.

Catt became the singles champion at the 1963 British Covered Court Championships after three-set victories in the semifinal against Ann Jones and the final against Renée Schuurman.

Partnering Elizabeth Starkie, she reached the doubles final of the 1963 Pacific Coast Championships in which they were beaten by Maria Bueno and Darlene Hard.