First Peach/Fox match:
-watch Fox so that your turnip actually limits his movement. That's a tough Peach trick to master but it's ****.
-know Fox's range on his SH Nair so you can bait it easily.
-throwing out FC'd aerials is a good bait but it doesn't ork if you roll afterward
-jab to dsmash is good if fox starts to spotdodge
-I'm guessing you're having a hard time keeping your eyes on fox because you're throwing out moves too early and he's running away from any pressure you put onto him
-actually, stop shielding after you aerial(even if you missed). This is a good thing to remember because it keeps you moving and unpredictable.
-when edgeguarding firefox, go out there.
-unless you're low to the ground or Fox is shielding Dairs are probably not the best option
-follow up landed Bairs with Dsmash(lower %s), grabs(low/mid %s) or dash attacks(mid/high %s....if it still hits at high anyway).
-**** on his last stock =)