For a date, why some girls dress up as if they were going for a church service?

This friend of mine always wears turtle neck collar and long sleeves and long skirt on a date? And she keeps her long hair in a tight bun. She rarely gets asked out again. I suggested to her to dress up in a manner that will raise the guys interest - low neck and high hemline, with short sleeves, hair down. But she won't agree with me.
I think she appears to the guys like a primary school teacher disciplining a wayward boy.
She really is a nice girl who is looking for Mr Right.
Is it natural for a girl to behave this way?
For a date, why some girls dress up as if they were going for a church service?
Post Opinion