Also, Siso earned a championship ticket in the doubles with new partner Lee Na Young of Korea.
In the girls 12-under, Siso of the University of San Carlos-South Grade School and is supported by Dunlop and Osaka Iridology broke the heart of another Korean, Park Soyeon, 6-1, 6-4, to book a final seat against Choi Jihee, also of Korea.
In the doubles, Siso and Young scored a 6-3, 6-2 win over Park Sohyeon and Park Soyeon to meet Daun and Choi Jihee in the finals.
Before the Langkawi outing, Siso already managed a grandslam finish after winning the singles of the girls 12-under in Selangor, Penang and Perlis.
On the other hand, Vince Marc Tabotabo settled with another bronze in the boys 10-under doubles.
The tandem of Tuburan Elementary School, Accord Bank and Tavo Sports-sponsored Tabotabo and Jurence Mendoza put up a good fight in the semifinal round, but ran out of gas in the deciding set to Mohd Nur Amin and Mohd Ali Imaran, 6-7 (3-7), 6-4, 6-1.