CREATE TABLE table_204_975 (id DECIMAL, "year" DECIMAL, "competition" TEXT, "location" TEXT, "event" TEXT, "final-rank" TEXT, "final-score" DECIMAL, "qualifying rank" DECIMAL, "qualifying score" DECIMAL)

what was the only event that she participated in the vault ?
SELECT "competition" FROM table_204_975 WHERE "event" = 'vault'
SELECT "competition" FROM "table_204_975" WHERE "event" = 'vault'