Because every girl is a Princess - I like this one
A girl should be two things classy and fabulous - This doesn't even come close to rolling off the tongue or sounding like a tagline. Wouldn't use this one
The perfect gift for your Princess - It's ok at best. It's like stating the obvious though.
Hair accessories for your little Princess - again it's ok. Expected.
Oh and I never cared about the princess stuff but my daughter loved it. She's 8 and starting to go away from it but she still loves bows and tutu's. Everywhere I go people sell their custom bows, tutu's, pillow case dresses. I don't care what the name is on the booth. If I like the product I buy it. When I'm buying boutique stuff I either buy it when I see it on display at the shows or fairs 90% of the time right on the spot or if I decide I might want something custom I want the person's actual name and email address. I could care less what they've tagged their boutique booth business. For that matter I buy custom made beads, bows and lots of other things at fairs and shows. Some I go buy from every single year for years.
I couldn't tell you even my favorite ones what they call their boutique business in a million years. I can tell you their names though. So I wouldn't worry too much about that. Name it whatever makes you happy. I'd personally stick to whatever I'd already been using.