lol sorry had to go with a LOTR quote there. Basically i was approaching her with either SH or FH needles into a dtilt and then ftilt to fair or whatever. but she figured out the CC and that her dtilt can combo into her dsmash. I can ALWAYS beat her in the air but i have trouble getting her there. she stopped using float so much and hugs the ground. how do i get her in the air. should i just spam more needles? her dash attack has more priority than God I believe.
This is a band-aid, because it sounds like your ground game overall is underdeveloped, but my immediate solution would be: Why are you needling into tilts?
If they're giving you needle opportunities like that, I'd think that grab would be better anyway. Immune to CC, and if you know you're off you can just DD and wait for them to sidestep, D-smash, or shield because 70%+ of Peaches are idiots.
I would also say that you're correct that you should probably camp platforms and try to make her go airborne if you're consistently beating her there. Figuring out how to make them go into your strong zone is a part of this game, after all. Sheik also conveniently has a camp game comparable (better, in fact) to Peach.
For D-tilt and stuff if they're zoning with it, learn how to dash dance and space with your movement effectively.
I'm guessing Armada covers "everything" with his tech skill, movement, spacing, and float-cancel, which is why Amsah says Sheik is completely useless against a Peach that can do all that. However, I'm going to make a wild guess that your opponent can't do all that. So I think dash dance and learning how to space via movement will be a useful thing to work on.