A member of Brown's Gymnastics club in Orlando, Florida, Johnson made an impressive debut in high-level competition, winning the all-around, vault, floor exercise and balance beam titles at the 1986 Junior Olympics National Championships.

She qualified for an event final on the vault, for which she placed fifth (however, had the competition been held under the New Life rule as in 1989, she would have won the silver medal).

It was a successful year for her, as she nearly swept the US National Championships, winning the all-around title and every event final, with the sole exception of uneven bars.

She also achieved outstanding results as a member of the fourth-place US team at the 1989 World Artistic Gymnastics Championships, coming in second on the vault and seventh in the all-around.

When Erica Stokes was unable to compete after sustaining an injury, the USGF asked Johnson to replace her.