What are the "forms of flight" in the short story "The Leap"?

The narrator of "The Leap," the daughter of the trapeze artist known formerly as Anna Avalon, states that her mother exchanged her one form of flight--soaring through the air into the arms of her husband Harry Avalon--for the "flight" of the mind obtained through reading.
Leaps through the air
The Flying Avalons were a spectacular circus act. As Harry Avalon, blindfolded, swung by his knees, his wife Anna, also blindfolded, would leap from her shining bar into his arms, kissing him before she grasped his hands. However, after lightning struck the main pole and "sizzled" down the guy wires, Harry tumbled to his death, but Anna was able to save herself, although she was injured.
Leaps through the imagination
While she was in the hospital of the town where the circus was held, Anna fell in love with her attending physician, who monitored the set of her arm, which was "complicated." He would sit by her bedside and Anna would entertain him with tales of many of the places he yearned to visit. Thus, through his listening, the doctor made "leaps" of imagination to these untraveled cities and countries.
This physician repaid Anna for her descriptions of so many interesting places by teaching her to read, a skill she had not learned because she began her circus career so young. Being able to read helped her overcome the boredom of being confined to a hospital room as well as her grief and desolation after the loss of her husband and unborn child. The narrator observes,

I wonder if my father calculated the exchange he offered: one form of flight for another. For after that, and for as long as I can remember, my mother has never been without a book.

Both the narrator's father and her mother made "leaps" of the imagination; one traveled as he listened to tales of faraway places, and the other traveled on the pages of books.