She is still on my Facebook why?

[ashley]

A friend of mine last summer requested me on Facebook and I granted the request. She had a few photos of her child but a few months later she puts photos of herself and her child and then I sent a message to her saying  "nice photos"And she replied "thanks".
Then shorty after that she restricted her photos. 
I didn't mind but she restricted her messages too of her friends but it was in a different language so it was pointless to do so.

she is not good friends with me but I am good with her. I feel she wants one way friendship so She can look at my non restricted photos of my family and wall and she restrict hers.
Her friends puts tags and I can see that, but is she aware I can.

I want to ask one question why did she request me on Facebook in the first place and if she is restricting me to limited messages and photos then why doesn't  she block me all together? I don't mind if she did and she doesn't like me anyway.
She is still on my Facebook list, I will not block her because I think it's rude to do so, and she is the only friend restricting her Facebook out of 50 friends.
It seems strange to me. If she thinks I'm a weird person the why request me.

I would like to know why that's all what is the reason behind this. If you don't like a person then block them Or never request them in the first place. 
What a strange friend.