Emblem: I met Shane in the U.S. a bunch of times. SW at Pound 3 as well. If you ask any really good Fox player, they will tell you their hardest/most uncomfortable match-up is Falco. Either that or Jiggs/Samus. I don't have to ask Shane or Otto to know, I've talked to PC, Wobbles, Sliq, and Tuar about it. Falco has more priority than Fox in general, and eats every move without question. Unless Fox can weave around his hitboxes and lasers, its **** hard to win.
Good Peaches will SDI the dair? Xif, Vidjo, Xelic DoH...or any of the good Peaches I played in the U.S. didn't d.i. any of my dairs. Nor did any good Peach d.i. PC Chris' dairs in matches. Do you have a super amazing Peach hiding in WC that can do this consistantly?
If the Foxes you know run around spamming dair into Peach without thinking...then I can see where you're coming from. Fox ***** Peach if he approaches carefully. Lasers, abuse the lag when she misses dsmash and punish. Uthrow uair after copious amounts of DD->force your opponent to lag some more->grab.
Peach has no speed and no aerial maneuverability. That being said, if the Fox is impulsive Peach dispatches him rather easily.