Mega Man Legends 3 designer Tokiko Nakashima took the fan selected heroine and modified her a bit. Before we get to her final look, here’s her original look as designed by Shinsuke Komaki.
Two weeks later Nakashima created "Aero."
This design evolution sheet shows how "Aero" evolved. Nakashima believed two important design points were her pink feather-like hair and the "chap" design on Aero’s arm. Nakashima tried to bring the chaps to her legs and changed the patterns a few times before settling on a more feminine floral look.
Number #4 is particular interesting since Nakashima tried making "Aero" younger to find a balance between Roll and Tron
A design doc posted on the Capcom blog explains "Aero" is a 14 year old girl. She’s optimistic and jumps into situations head first, often without thinking. While "Aero" is an operator, she is also absentminded and doesn’t know much about machines. "Aero" has a love interest in Mega Man Legends 3. She falls head over heels for a powerful and rash [censored character name.]