My friend plays Peach, so I'll give some input.
YOU CAN'T, ****ING, GIMP, PEACH WITH TOOLS! IT'S IMPOSSIBLE! (FLUDD and Cape both send her upward, if you cape her jump beforehand (nearish to the stage) she can make it back easily due to how her Up-B works, darn floatiness.) Use aerials instead.
If they like to use the toad, draw it out, and CAPE. They take the cape damage + spore damage + increased KB.
FIHL works quite well on most of her aerials, but you usually can't follow-up, especially if she was floating. (I don't use it often enough though -_-',)
Get in her face, THE WHOLE TIME, and it's hard for her to get out of your range, just watch out for the Nair and Dair (What I typically see as a GTFO me move while fighting aerial Peach), and you should be fine.
The turnips are pretty easy to deal with, you can either fireball/cape/aerial/tilt/jab/fludd them. (Peach can do some messed up crap if you get hit by a turnip though.)
And for the love of god, don't get hit by a bomb-omb, it doesn't happen often, but it's scary as **** if they happen to get one in killing percents. (So... make sure you watch what they pluck)
Not really sure what the whole matchup result would be. But yeah, I'm tired of playing Peach.