Complex sentence: She started training Karate at age four and pursued training in Boxing at the age of sixteen and began training in Brazilian jiu-jitsu after being invited to the dojo by her sister, who also trained in the sport.
Split into simpler sentences: She started training in karate at age four and pursued training in boxing at the age of sixteen. She began training in Brazilian jiujitsu after being invited to a dojo by her sister, who also trained in the sport.