Scarlett

Scarlett is a female, Flame-Colored Tanager and is the sister of Whistle and Pilot. Due to a scramble in genes, Scarlett, along with Whistle, both take the appearances of males, while Pilot takes on the appearance of a female, much to his dismay.

Backstory
Scarlett, born along with her two siblings, was raised by one single parent, her mother as her father was not around to take care of them. Despite being oblivious to her brother's hatred of her, Scarlett got along rather well with Pilot, rather than Whistle. When the three were ready to fledge, Scarlett was the second, the first being Pilot and last being Whistle.