WOW a child has a great event and suddenly this is about you?

I'm sorry you feel hurt...that isn't good for you to feel that way...
If she is such a friend you would have been able to ask her about it already. If you have been in contact all along, wouldn't you know about it anyway? It sounds like she uses FB and expect all her "thousands" of friends to just read and know...not having time for real friendship, perhaps, and making the effort that those who care were informed.
Sigh. I would not be hurt. Maybe in a younger day, but no one can hurt me now, their opinion of me is none of my business. I am who I am and who they are isn't affecting who I am.

Feel better soon...and hope you find some real friends hon.