Of course if I was you I would ask why wouldn't I be able to go. Wait until she gives a reply. There could be a side to her that she doesn't want you to see! ::) There could be another male friend she's seeing. Don't get your hopes down she may just want to hang with the girls! After all it is the prime of her life!

:)No doubt that your feelings are sincere and your attachement is intense,but the element of"mutuality"is missing.She's in the peak of her youth,it is obvious she wants to enjoy life to the full and burns the candles at both ends... so why depriving her of this"right" and of all of self-improvement and for your part,stop deaming up plans to "gain her".To speak true your love is not returned... you should change your tune.
God Bless
Noredine

You know I don't know what your question is because I was not able to view it, but advise from the previous expert sounds good... people no matter what gender need room to explore and live life to its fullest and it looks like your firend is at that point in life either accept or move to the side.who know if you go for what she wants it might be fun.Best of luck and God bless

Chaz :)