Rubuta ci gaba ga wannan sakin layi - Sergent ta yi ikirarin lashe lambar farko ta duniya a gasar zakarun duniya ta 1987 IAAF ta kasa, ta doke Liz Lynch da dakika biyu. Ta kuma jagoranci matan Faransa zuwa na biyu a cikin rukunin rukunin bayan Amurka (wanda Lynn Jennings ya jagoranta). Farkonta a Gasar Cin Kofin Duniya ta 1987 a Wasannin motsa jiki ya biyo baya kuma ta rasa wasan karshe, ta gama na takwas a cikin zafin ta. Ta fara kakar 1988 tare da cin nasara a taron Cinque Mulini da tseren Gasar Faransa. A Gasar Cin Kofin Duniya
a Auckland ta kasa riƙe taken ta amma ta lashe lambar yabo a shekara ta uku a jere, ta ɗauki lambar tagulla ta mutum da ta ƙungiya a tseren nesa. A kan hanya ta kafa tarihin kasa a cikin mita 3000 da mita 10,000. Ta kasance ta karshe a duka abubuwan da suka faru a Wasannin Olympics na Seoul na 1988, inda ta kammala na 12 da na 19. A waccan shekarar ta kasance ta biyu a kan mita 5000 a gasar IAAF Grand Prix Final, inda ta zama ta biyu ga Liz McColgan ta Burtaniya.