According to the text, how does Earhart's credibility as an aviator develop over time?

His instructor did not give him much credibility as a pilot, an opinion he would not abandon during his career, but in October 1922 he achieved his first altitude record by flying at 14,000 feet (4,267 meters) high. By 1923 he obtained the license to pilot of the International Aeronautical Federation, being the sixteenth woman to receive it.

Explanation:

In April 1928, Amelia received a call that would change her life: Captain H. H. Railey asked her if she wanted to be the first woman to cross the Atlantic Ocean. The idea for the adventure had been from Amy Guest, an American aristocrat who had purchased a Fokker F. VII. At first, she was the one who would pilot the ship, but, under pressure from her family, she had given up. The Guest family then hired George Putnam, a New York publicist, to find the right woman.