would it be weird to fb message a girl that you have never talked to?

[Jules]

i did this show (prodution) for about 2 months and it just finished. anyway there was this very nice looking girl that i never managed to talk to because i only really noticed her right at the very end. me and a friend are hosting the after party for the show and i was wondering would it be weird for me to ask her on fb if she was coming as a way to let her know that i exist (for all i know she barely noticed me) and maybe to let her know that im kind of intersted in her and to maybe help break the ice for if she is going i am planning on introduing myself and try to get to know her.
or should i just not ask her and hope she come to the party then introduce my self for the first time in person to her?