Born in Topeka, Kansas in the year 2351 to two Q parents, she was raised as a Human on Earth. As a result of her birth, the Q Continuum executed her parents with Amanda being adopted by two marine biologists. Amanda grew up unaware of her true heritage but occasionally brought objects and creatures into existence based on her subconscious desires. As she grew up, this attracted the attention of the rest of the Q.
In 2369, Amanda received an internship aboard the USS Enterprise-D under the mentorship of Beverly Crusher. After Q had subjected her to several tests that revealed her reality warping capabilities, Amanda was made aware of her heritage. Though Amanda initially decided to renounce her powers so she could stay among the humans, she was compelled to use them to save Tagra IV, departing for the Continuum with Q. (TNG episode: "True Q")
A decade later, after Q had angered the Prophets during his God War, Amanda mended diplomatic ties between the two races. Seeing how unhinged Q was becoming in the conflict, Guinan requested Amanda's aid, along with that of Wesley Crusher and The Traveler, to end the conflict. After all four of the abducted crews had been brought together, Amanda gifted them Q weapons. When Q later agreed to a peaceful resolution to the war, one of his terms was for Amanda to surrender her powers, something she gracefully accepted. Q later took Amanda home and made it so she could have a career in the biomedical sciences. (ST - The Q Conflict comics: "Issue 4", "Issue 5", "Issue 6")