6 weeks old is a month and half. She's too young and should be with her mother.

Perhaps she's been abandonned by the family who had kittens as it often happens, or the mother is dead.
Then she's lucky that you're here to help her. But she might be more agressive than some cats when she'll grow up because her mother didn't have the time to teach her everything.
Still, since you don't know where she's from, you should ask people if they have lost a kitten (perhaps write this in a local newspaper).