different colors deep purple iphone 14pro

I would take both phones to where ever purchased from (if you got it from Apple and have a store nearby go there) and have it inspected. If hers is still in the return exchange period she can request a replacement. Typically the Apple warranty doesn’t cover cosmetic issues but it’s possible they will address this once they see it.

Are you certain both phones are the identical same model iPhone?

On each iPhone open the Settings App.

Tap General, then About and check the model numbers to make sure they are the same model iPhone. If they both display the exact same model number, the colors should match. If they don't, they aren't the same model exactly.

Are you sure hers is indeed purple? Meaning does her box identify it as purple or space black? Have y’all had them since launch and the color seems to have changed over that time?