Delilah finished her warm ups and then found and updraft to ride on. She flew up to about 20,000 feet so the island was tiny beneath her and checked her breathing in the thiner air. Then she shot off northward, going as fast as she could. Taking a change she flew away from the perimeter of the island and far enough that the island was out of sight. This took about 20 mins Then she turned around and just glided back to the island with her wings spread. She was breathing rather hard so she dropped a thousand feet to take a rest. 

She flew back to the island and flying back took about 40. She sprinted the last mile and landed on a sandy beach at the edge of the island. Falling onto her back in the sand she panted as she tried to catch her breath. Her heart beat hard and fast in her chest and she laughed breathlessly, relishing the soreness of her wings and the pain in her lungs. When she could she stood and began jogging back to the academy.
(lol, Delilah doesn't care if she's late to class.)