If you're on the hunt for a quality hair stylist, you should judge the book by it's cover.
If the person that could potentially be doing your hair has damaged, unhealthy hair, politely end your appointment inquiry, ask for a business card and toss it a couple blocks from the establishment. You should also take a hard look at her clientele . It's one thing to know someone who goes to that stylist and pays a decent price but it's another for that person to leave that chair with over-trimmed, over-processed or fried hair.
I say this from first-hand experiences. There was a special going on at one of the salons in my best friends neighborhood. Long story short, when I went back to my usual hair dresser, her exact words were, "Who did you go to? She messed you up bad. She messed you up real bad." She was referring to the uneven hair cut I received after specifically stating that I wanted a trim. I also sat in that salon for about 6 hours.
You live, you learn.