Do you think it would be awkward for me to my crush's sister on Facebook?

[Sunshine on a Cloudy Day]

My crush's sister. His sister and I do not know each other, but my crush told me that his sister goes to our school too, and that she is in my grade. We do not have any mutual friends, except for her brother/my crush.

So would it be awkward too add her, even if I was to tell her who I am, and that her brother mentioned her a while back?

[Hailey Sigsworth]

Wow, Im like, in the same situation. But me and my crush dont talk. -_- I dont think it would be awkward. It would just be sort of starnge to her. But she miiight accept it. There's a good chance that it will happen.