Guest F

Guest F is a Pre-loaded Mii available for use in titles that feature Mii support, which includes Wii Sports games, Wii Party games, and other games with Mii support.

She has white skin, with brown hair and black eyes. The basic girl in the Mii Editor is the same that Guest F except that her favorite color is red.

Super Smash Bros. for WiiU & 3DS
The design of the Mii Gunner used in promotional material and in-game renders is based on an edited version of Guest F. In this case, her hair uses a different design and color from the preloaded version, along with a smaller mouth and a different favorite color (orange instead of pink). She is also based on the default female Mii in Mii Maker, though again, with a different hairstyle and color (red instead of pink).

Super Smash Bros Ultimate (Switch)
The Mii Gunner in the Switch game isn't the same that the Mii Gunner in Super Smash Bros for Wii U & 3DS but is also based on an edited version of Guest F. She has a different haircut (Same as Clara's one. However, her bangs is going on the opposite direction.) and her hair is dark brown. Her nose and mouth are smaller and has a different style. Her favorite color is yellow instead of pink.

Trivia

 * You can earn her badge for making 50 edits on "CPU Mii" articles, which is now disabled.
 * All you need to do to make her Mii is to change the default female Mii's favorite color to pink.