well, I don't really play peach, but since she has good movility in the air, I guess you want your opponent between you and the ledge, go for a gimp since I really doubt she has killing power, you can make use of her aerial options, since she can stay in the air you can pressure your opponent into doing a reckless recovery, like I said I don't play peach but that's one of the way I would use her xD
and you should play more gafers too, perhaps you had only played against the best ones xD your level is good enough to put a though fight here, keep it up!