[1] At the New Zealand national tennis championships in January 1959, played at Wilding Park, Christchurch, Johnston reached the quarter-finals of the women's singles, where she was defeated 6–4, 6–4 by Betty Nelson.
[8] In early January 1960, Johnston was defeated by Ruia Morrison, 6–3, 6–4, in the women's singles final at the North Island tennis championships in Hamilton.
[14] At the New Zealand national championships in Wellington, Johnston and her partner Judy Davidson defeated Morrison and Raewyn Ferkins, 4–6, 6–4, 6–3, in the final of the women's doubles.
[5] At the 1965 National Lawn Tennis Championships of India, played in New Delhi, Law defeated Asian champion Nirupama Vasant, 6–4, 6–4, in the final of the women's singles.
With her partner, Begum Khan, Law also won the women's doubles championship, defeating Nirupama Vasant and Leela Punjabi 2–6, 6–3, 6–3 in the final.
[17] The following year, at the Indian championships, Law beat American Carol Prosen 6–0, 5–7, 6–1 in the women's singles semi-finals,[18] but was defeated by the Soviet player Tiiu Soome in the final, 6–2, 3–6, 6–4.