Ty Lee was a former Kyoshi Warrior, and once an enemy of Team Avatar before joining them following the War. She was a typically upbeat and cheery girl, even down to her last days. Ty Lee easily made friends during her life, including sharing a series of close friendships.
Ty Lee was born on the 13th of March, 86 AG, into a family of several identical sisters. In her life, she encountered difficulty in getting a unique identity, and as a result, ran away from home to join the Fire Nation circus.
Early in her life, she attended the Royal Fire Academy for Girls, where she met and befriended Mai and Princess Azula, though she would later betray the latter.
After running to the circus, in 100 AG, she was recruited by Azula for a mission to hunt down Zuko and Iroh. She initially refused, but after Azula used scare tactics at Ty Lee's circus performance, the acrobat had a change of heart and joined the princess. They traveled to Omashu, where Ty Lee reunited with Mai. During this trip, the three encountered Team Avatar. Eventually, a long chase would ensue over a period of months, before Ty Lee and Mai later betrayed Azula.
For far more, please see the Ty Lee page on Avatar Wiki, located here: Ty Lee
At the end of the War, Ty Lee and the Kyoshi Warriors were released from prison. She then re-met with former enemy, Suki, and, alongside the other warriors, convinced her to become a part of the group. This made her the first known Fire Nation native to join the warriors. They then re-donned their old uniforms and were present at Zuko's coronation.
After the coronation, Ty Lee made friends with Team Avatar. She apologized to the group for her actions member-by-member, and they agreed to accept her in. Most notably, she had an open, heart-to-heart talk with Katara, which turned their bitter rivalry into a close friendship that would last for life.
Suki then left with the rest of Team Avatar to Ba Sing Se, and chose Ty Lee to oversee the warriors while she was away. Ty Lee moved full-time to Kyoshi Island, and for the next two weeks, advanced the girls' training in chi blocking, which she had taught them in prison. Suki returned to the island and again took the reins, though Ty Lee later gave her chi blocking lessons of her own.
During this time, Ty Lee advanced her friendships with others, while retaining her old friendships. She frequently wrote letters across the world to the other members of Team Avatar. Most notably, she exchanged most of her letters with Katara, while Suki wrote others to Sokka. Occasionally, the two Kyoshi Warriors ventured to the South Pole.
A year after the War, Mai called on the warriors to come to the Fire Nation after several assassination attempts against Fire Lord Zuko. The girls provided protection for him and then the capital as a whole while the crisis in Yu Dao took over the world flow.
After the Yu Dao Resolution, which led to the creation of the United Republic of Nations, the Kyoshi Warriors returned home.