birthday dilemma?

[Charlie]

Basically it is a girl's birthday who I "like-like". On Facebook,as I couldn't go to church and wish it there, I want to say "happy birthday".
The problem is I don't want another guy to see it as he will joke about it. I know most people post happy birthday messages on someone's wall , so would it be unusual to inbox her it?
Also, should I only do it when she is online?
Or shall I just leave it- possibly wish it to her another day?

Extra info: I liked her profile pic she put up yesterday and it's late evening where we are from.

This probably sounds silly to you, but thanks in advance

[Cody]

Just post on her wall happy bday. Follow the norm. Unless you want it personal then message her. Even if it's late, she will know you care