She didn't. None of them did but that was the point wasn't it? Tilly made the dresses so beautiful for them thinking that they'll be a better version of themselves, transforming them to be a better to a whole other person while in fact worsening their intentions and character. Like what Dr. Erskine said in Captain America First Avenger: "Good becomes great but bad becomes worse"
Of course the whole makeover is a package But I still say it’s started from the dress. I don’t know how to explain it, but from what I experienced, whenever I try on a “fancy dress”, it gave me more confident, some short of feeling like I’m fabulous, it then encourage me to put a ‘bold’ make up on and change of a hairstyle so it will match the dress. But it won’t work the other way around, maybe just me 🤷🏽♀️. Imagine her with those gorgeous make up and hairstyle BUT paired with the type of dress the other girls in the room wear. It wouldn’t scream ✨MAGIC✨