Automail is amazing as-is, but I think Winry would have fun helping out a patient who wanted not only to have cool automail but to look cute too.
As a kid I spent a lot of time in pediatric orthopedics hospitals (long story), and I was always fascinated by the fun out-there designs available on prosthetics. Though automail is cool and steam-punky it doesn’t seem like anyone in canon was paying attention to its aesthetic appeal for kids, and I can imagine Winry really getting into that.