The 1988 season was Tooby's most successful: she became the UK Cross-country Champion and, following a win at the prestigious Almond Blossom Cross Country race, she won the silver medal at the 1988 IAAF World Cross Country Championships, behind Ingrid Kristiansen, and led the British women to a team silver medal as well. She attended her first Olympics soon after, but in the women's 10,000 metres at the 1988 Seoul Games, she was eliminated in the heats (following a stress fracture of the spine). Her compatriot Liz McColgan took the silver.