Lhein, incorrect information. There's a difference between curly and frizzy. Curly hair can get frizzy, but frizzy is not a hair type, it's poor hair condition. If she says her hair can get curly, then her hair can get curly.
And no, nothing would go wrong if she told a hairstylist if her hair was curly. Plus if we're good, we can tell when someone's hair is naturally curly or wavy, and has been straightened.
The only time curly hair makes a difference in haircuts, is for shorter haircuts, and bangs/fringes.