In 1950 Markus qualified to play for Britain by virtue of her naturalisation. Her first partnership was with Lady Doris Rhodes, a good player who had played on "Pops" Beasley's British team in its 1933 match with the Culbertson team. Markus–Rhodes played together in the "Ladies" flight of the European teams championships in 1951 (Venice) and 1952 (Dún Laoghaire or Dunleary), winning both times, and in a 1953 tour of the United States where they played in two victorious matches against the American ladies team.