The youngster overcame a jittery start to form a solid partnership with La and beat New Zealand 3-1 in the final at the Bluesky Sports Arena.
La spearheaded the mixed team’s campaign with a 3-0 (11-8, 11-9, 11-9) win against New Zealand’s Lydia Mercer-Beumelburg.
Tua was unable to beat Emily Jin however, going down 0-3 (1-11, 10-12, 3-11) to level the match at one-all.
But La and Tua combined well to beat Mercer-Beumelburg and Jin 3-1 (11-8, 6-11, 11-2, 11-9) in the closely contested doubles clash before La sealed the 3-1 win with a 3-0 (11-7, 11-9, 12-10) victory over Jin.
In the other matches, Cook Islands finished fifth in the cadet boys team event after beating Wallis and Futuna 3-0.
National reps Anjoninah Marsters and Ngamata Moekaa played for the mixed team in the junior girls category and lost to New Zealand, Fiji and China, going down 2-3, 1-3 and 0-3 respectively.
In a feature match, the mixed team of Australia, New Caledonia and USA combined to claim gold, taking down China 3-1 in the final of the cadet boys team event.
It was a stunning upset, particularly given what had happened the previous day when the mixed team were beaten convincingly by China 3-0.
Meanwhile, Mixed Team I of Jacobo Vahnish (Panama) and Koen Pang (Singapore) defeated Mixed Team II of Laurens Devos (Belgium) and Owen Cathcart (Ireland) 3-1 in a fiercely contested junior boys final.
Cook Islands’ Toka Williams and Jonah Moeauri finished fifth in the division after beating Wallis and Futuna 3-0.
The competition continues until Saturday.