this... the only peaches ive faced thus far are kyon/flatsoda dunno how they are as peaches but i felt rather comfortable fighting them o.o. comfortable in a sense where i nullified there air game through predicted jumps (punish with a buffered fair) or a sh thrown banana>follow up with an air attack or wait for them to touch the ground and depending on the situation/opponents defensive style/placement of other banana> tech chase.
Regardless though, all Peach can do is dair, FC, nair (shield poker), and fair. Once u catch on to how that player utilizes those 4 movements, itz easy to counter.
Now a Peach who can work the air and the ground simultaneously can pose a much larger threat.
tho i think its still hard :\