Should I have one of my friends talk to her?

Well, there's this girl, and I like her. I took her to my school's homecoming dance alst month, but it didn't go so well. It wasn't bad, she just didn't hang out with me very much there. I planned on asking her out some time after the dance depending on how it went, but it wasnt good so i just gave up for a while. but i wanted to give it one last try, so at my school's last football game i asked her out, and she said it was a bad time because she was having problems with her ex or something, but that i was a good friend...and now idk what to do. I really wanted to ask her to Winter Formal, but idt that she willsay yes after me asking her out and kinda getting rejected. I want to know if she really doesn't like me or what, because there was a short time alst year when i thought she liked me. So, i was thinking about having one of my friends talk to her about it. Good idea? Bad idea? I don't really want to talk to her about this, and i feel for some reason that it would be better to hear thru one of my friends. Help?