Calling all teens and wise for help!...Should I let my 14 year old daughter go or ask that she come with me?

My 14 year old daughter worked very hard all year and got fantastic grades despite her medical problems. The end of this week she wanted to celebrate in a sleep over with her girlfriends. I said Cool!, then...I learned that Saturday they all plan to see a ban of hot guys play in T.O. That's the same day as my own graduation from University. I studied part time for 9 years because of LDs and to be with her. I feel so sad at the thought that she won't be there. This was so important to me. She and my husband are all I have and this is the only "big thing" I've ever done. On the other hand it'll probably be a boring long ceremony at a time where all her friends will be together hanging out and having a great time. I don't want to guilt her into coming, but I am so sad to not have her by my side on the day of my graduation, I also fear she may regret later not having come...I am not even sure if I want to go without her :( ...I should mention she is really a very nice and considered girl, but she is 14 now and friends are becoming way more important and fulfilling in her life than family time. Also she had not realized that my graduation coincided with her plans until today.