Peach advice? Sure!
I know samus loves her cc, much like peach loves hers, so I try to bait that then punish with this one really gay attack that does like 70 damage. I have most trouble with seeking missles, Peach is mad slow, and bumping into little 5 damage projectiles tends to slow her down, also it keeps her grounded as it interupts her float. If I were to be the samus in this matchup, I'd try to play this entire match from across the stage. Save your charge shot for the one moment that you know it will land, generally peach players have consistent powershields. Use Smash Missles as kill moves on YS and at high percents.
If you do need to approach/fight close up, remember to keep projectiles in the air. Once again, your seeking missles just sorta float in the air, and gives peach less movement options. Avoid the fair and other FC aerials.
This is the clash of samus vs peach. Samus loves her OoS game, she has a wonderful up-b oos and can do all kinds of wd oos tricks, just look at HugS. Peach, though, is the queen of shield pressure. If she FC Nairs at a frame perfect rate (that I can almost hit!), your opponent cannot let down their shield. So technically, though Up-B oos is not negated, it is made much less effective. My advice would be wd oos back, and start spacing projectiles.
Fsmash and Nair are close killers. Dair is good sometimes, but don't count on it.