I'll take a few more knocks at it.
Peach's forward smash - Well it wouldn't be out of place for Daisy to be swinging sports equipment, now would it?
True but its the frying pan where I get thrown off. Peach used that in a Game & Watch remake.
Turnips - Turnips only became heavily associated with Peach
because of Smash. In SMBUSA, anyone could pull up turnips, and in the hypothetical situation where Daisy is playable in an actual Mario game, she'll be using the same tools as everyone else.
Also true, but Daisy wasn't in that game. There's been moveset ideas where Toad utilizes the turnip pull as well, but only Mario, Luigi, Peach, and Toad would be the ones using it. Daisy wasn't in the game, but I do understand what you mean.
Hearts - Daisy's special item in Double Dash. Didn't even need to try.
Ah, this little argument. Another pity from this amazing game, seeing how Luigi got his green fireball and Birdo got her own egg, but those were minor colorations. This is basically the only game where Daisy uses hearts though.
Parasol - Would it be that out of place for a princess from the desert to have something to block the sun with?
Logically, no. But the majority of moves are derived from games where the character has actually used them (unless you're Captain Falcon and R.O.B.)
Toad - I don't see why Daisy wouldn't want to borrow a large, mushroom shaped creature from Peach. ( ͡° ͜ʖ ͡°)
Sharing is caring ( ͡° ͜ʖ ͡°)
Final Smash - Alph again. Also, when have the Koopalings
ever turned into Shadow Mario?
Someone prior mentioned that since Olimar and Alph's team met that he lended his ship to Alph and Alph is also seen in the End of Day trophy. Koopalings are probably just using Bowser Jr.'s tools himself. HOWEVER!!! with the way you asked "have the Koopalings ever turned into Shadow Mario?" let me activate my trap card by asking:
- When has Daisy ever picked turnips (that isn't from Mario Party, but I believe that was carrots)
- When has Daisy utilized a parasol? (technically speaking this was an original move for Peach like Peach Bomber. Peach didn't really use an umbrella 'til her own game, but this could also be a reference Sunshine) ***CORRECTION: She first used a parasol as a weapon in SMRPG)
- Does Daisy even has servants to begin with? If she does, they're most likely not Toads.
You trumped me with the Hearts since she did use them in MKDD, but I got you with these ones friend