James initially represented Rhodesia at the 1972 Summer Paralympics, competing in athletics and swimming.
This was to be Rhodesia's last participation in the Paralympic Games. Shunned by much of the international community, the country was embroiled in the Rhodesian Bush War by the time of the 1976 Games, and did not take part. Rhodesia's successor state, Zimbabwe, began to participate in the Paralympics immediately upon coming into being, and Sandra James returned to the Paralympics as part of Zimbabwe's delegation to the 1980 Games.
In 1980, James took part in athletics, swimming, lawn bowls and table tennis.
In table tennis, James and Robertson were one of three pairs competing in the 1B category. They were defeated 0–3 by Norwegian team Marit Lysen and A. Klausen in the semi-finals. In the other semi-final, Mexico were non-starters against Ireland, resulting in a walkover. Norway defeated Ireland in the final, for gold; no bronze medal was awarded. James fared better in the singles, where she was one of three competitors in the 1A category. She lost 1–2 to J. Toomey of Ireland, but defeated Mexico's Josefina Cornejo 2–0, and won silver.
