Final answer:
Mairs made the important life decision of becoming a news anchor when she was 19 years old.
Step-by-step explanation:
In her essay, Mairs reveals that an important life decision she made when she was only 19 years old was to become a news anchor. At the age of 19, Mairs became the youngest and first African-American female news anchor. This decision shaped her career and led her to become a successful media giant known for her intelligence and empathy.