Competing for England, Powell-Tuckett claimed bronze in the girls’ B platform final on Sunday morning and also came eighth in the three-metre final.
In the platform event, the Plymouth diver scored 271.85 points to finish behind her Great Britain team-mate Amelia Connolly (303.85) and Italy’s Chiara Pellacani (272.70).
Meanwhile, Piper, competing up an age group in the girls’ C category, could not have come closer to a medal.
She finished fourth in the platform event and fifth in the three-metre and one-metre competitions.
In the three-metre final, Piper was less than one point off bronze.