Notes:

For those curious:
1. Spiky Eared Pichu is a definitively female Pichu in the Pokemon franchise, so she's listed here even if the other Pichu alts are "gender neutral"
2. I picked PikaLibre to represent Female Pikachu, having appeared outside of Smash and being way more popular and unique than "other Female Pikachu with a hat", even if that one's listed first in the costumes like Inkling and Villager's are.
3. The Mii Fighters can have separate announcer clips for their different genders in different languages of the game like other multi-gender alt characters including WFT and Villager.