Can we draw the following hypothesis from the context?

Context:

Judy Tegart Dalton (nee Tegart; born 12 December 1937) is a retired professional tennis player from Australia who won nine Grand Slam doubles titles. She won at least one women's doubles title at each Grand Slam tournament, a "career Grand Slam". Five of her doubles titles were with Margaret Court. Tegart was the runner-up in 10 Grand Slam doubles tournaments.

Hypothesis: Judy Tegart Dalton was one of the first Tennis players of the era to also frequently compete in marathon races.
It's impossible to say