alright well to further explain with my knowledge of both series in the sense when it comes to Zelda (and I'm assuming this is composite since the profile shows all the Zelda's).
Zelda is a character whose entire magical strength comes from being a reincarnate of Hylia who was capable of using magic to do multiple things (which was showed off in exposition for skyward). But aside from usually very standard magical showing from Ocarina of times holding Ganon down or opening doors, or Twilight princess where she bestowed Midna with magic.
The best feats for her magic in the mainline would be from botw where she does impressive sealing magic. other than that the only other thing she has is potential yet doubtful sword skills due to a single cutscene in twilight princess and a much more determinable skill in archery with a bow/light bow.
The only reasonable version of Zelda to use for combative experience is the one from Hyrule Warriors where she is actually shown capable of using offensive magic in conjunction with her rapier skills. or where she can use the Wind Waker to command the winds, and the Dominion Rod which allows her to summon statues to strike her foes in a combo.
and here is where zeldas problem against peach can arise, Magic most if not 90% of zeldas main attacking methods come down to using magic in one way or another be it in CQC with Hyrule warriors Zelda who uses it to enhance her attacks and finishers, Be it with her long-range weapons like the Bow of light in which she fires Light arrows from which in most cases require magic or be made with magic, very rarely are they granted to her with outside assistance like the spirits of light. the only other option she has is once again straight magical attacks or her sealing magic (most of her magical attacks coming from smash bros some of which derive from links magic from oot).
but then there's sheik whom in the main games does nothing but teach links songs and use a Deku-nut to escape from Link in cutscenes (Ocarina of time), has standard CQC thanks primarily to smash bros which gives her Needles, a chain, and bombs. and Hyrule warriors giving her Magic which she uses in conjunction with the Harp to summon certain elements (fire, water, lightning, light, and dark).
Stripping Zelda of her Magic brings her straight down to CQC without any magical moves and depending on whether she had time to transform into Sheik her combative approach will be different. As Zelda, she'll most likely (using HW) use her rapier without magical assistance which removes her finishers and leaves her with only quick swipes and jabs, Can disable her ability to summon the winds with the Wind Waker, along with summoning the statue with the Dominion Rod.
Meanwhile, if she did transform into sheik being unable to use the harp leaves her only option being CQC with her only weapons being as I said earlier Needles, a chain, and timed bombs which she uses in a close range. (oh before I almost forget there's also her new FS which grants her a knife for a quick succession of attacks). And if you really wanna include this she also has her tetra form which she has more skill with a cutlass and a standard pirate pistol.
Peach on the other hand just has more options available that can counter Zeldas combative style, As I had mentioned before. Magic being Zelda's forte taking that away already leaves Zelda very open and alongside that peach can casually decrease the offensive power of characters like Bowser to the point in which he points out how easily he was beaten in pure combat of strength, And I doubt Zelda's nearly as physically strong in combat as bowser so peach doing her debuffing to Zelda will most likely leave her attacks unsubstantial in there effectiveness.
Along with this Peach can still use all her magic and CQC weapons/skills/items or power-ups. Plus Peach can summon Toads to counter-attack certain attacks Zelda/Sheik might try.
