While I don't think Daisy had "hit it big" she definitely had presence and I could see a melee-styled Daisy taking advantage of being Peach But X instead of Peach! Again! I could see the appeal if Dr. mario wasn't on the table.hmmm
Daisy hadn't really hit her big popularity, yet, I feel like that came after Double Dash.
I actually have a hard time thinking of 1 more clone for Melee
Maybe "Young Zelda" as a Zelda clone that has some gimmick where she summons Impa who is a clone of Sheik?
Baby Bowser, maybe? Mario Party had those Koopa Kid gremling things which were like Baby Bowser, so he was kinda still around, and Yoshi's Story made up the bulk of Yoshi's representation in the first few Smashes.
I'm not sure a "Young Zelda"/Impa would be in the cards, that'd be twice as much work load and it'd hilariously mean every zelda character had a clone.
Baby Bowser would be interesting, a Bowser about the size of Yoshi probably?
Hmm DK Jr? Jr was kind of on the outs already, but I think he'd be recognizable enough and double as a kind of throw back character.