An equestrian is someone who is involved with horses. You can also use it as an adjective to describe anything having to do with horseback riding. An aspiring equestrian may have to give up socializing with friends in favor of equestrian duties like grooming horses. Definitions of equestrian.

And since females make up 72% of all equestrians anyway, it is mostly a female sport. There is no special gender-related term for female equestrians. For awhile, the term Equestrienne was used, but…it fell out of usage. Judy Reinsma. Competed in Endurance and Trails competition for 30+ years.

Equestrian is the appropriate term.

Equestrianism (from Latin equester, equestr-, equus, 'horseman', 'horse'), commonly known as horse riding (Commonwealth English) or horseback riding (American English), includes the disciplines of riding, driving, and vaulting.