What kind of personality?

Some find it comfy, and like other people have said, she may wear a G-string so as to avoid VPL (visible panty line). Of course, if she's wearing low-cut jeans with a G-banger which is visible for all the world to see, I would say that she is OBVIOUSLY drawing attention to herself and as a girl I would say that is slutty. But if she's wearing one knowing that he will see it (in private, after having removed her other clothes) she is either a) comfortable with her body, must think she has a nice bottom and legs or b) thinking you will get turned on by it

I don't think you can generalize this one.
I have friends who wear them because they think it is comfy, friends who do it because their boyfriend likes it, ones who do it because it makes them feel sexy, women who do it because they don't want panty-lines, and ones who just want a particular set/pattern and the bottom part is a thong. I have thong and non-thong undies. While maybe her reasons for choosing thongs or the occasions on which she wears thongs might potentially tell you something if you knew the girl well, I think you would only be making unproductive generalizations by assuming wearing a thong means one thing or another without considering any other factors.

All it says is that she likes thongs. I own a lot of panties in just about every style available from 'sexy' thongs, to comfy boy shorts, and yes even one or two granny panties. All in different fabrics, from cotton to silk to lace. And sometimes, I opt for no panties. What's that say about me?

It says nothing but that I like whatever I'm wearing, or whatever I'm not on any given day.

Nothing. Its sexy and a lot of young women wear them.

She shaves, now if they black she wants to get laid usually. Good?

Nothing. Maybe she fells sexy! But that's it