Complex sentence: In her teens, Varian was mentored in horsemanship by Morgan horse breeder and cattle rancher Mary "Sid" Spencer, who did all of her own ranch work including shoeing, gelding, horse training, baling hay, and truck repairs.
Split into simpler sentences: In her teens, Varian was mentored in horsemanship by Morgan horse breeder and cattle rancher Mary "Sid" Spencer. Spencer also did all of her own ranch work including shoeing, gelding, horse training, baling hay, and truck repairs.