In November, at the final leg of the 2009 FINA Swimming World Cup in Singapore, Yeo reached the final of the three breaststroke events then closed out the year by finishing fourth in the 200-metre breaststroke at the 2009 Southeast Asian Games in Vientiane, Laos in a new national under-14's record time of 2:36.04, improving on Nicolette Teo's previous mark of 2:36.27 set at the 1999 Southeast Asian Games. This feat added to the national under-14's 100-metre breaststroke record she broke at the 2009 National Schools Swimming Championships six months earlier. Stopping the clock at 1:14.05, this shaved 0.02 seconds off Joscelin Yeo's time set at the Asia Pacific Swimming Meet in September 1991.