SHOULD I BACK OUT ON ASKING THIS GIRL OUT?

For two months i have been planing to ask this girl out. To me she is the most amazing girl ever. For the past two months ive been receiving what i believe to be symbols that she likes me. She asked me to be her partner for our trip to disneyland, she interviewed me for the school paper ( She chooses me out of all the people at my school ) She also always starts small talk with me and occasionally ask me to do things for her that she could easily do. This week has been full of turn offs and i need your opinion on what i should do. I was originally going to ask her out on our disneyland trip this friday but she is going to change partner from me to her other friend. Today when i was walking past her i also heard her mention how hot my friend was. There are a multitude of other things she said that made me feel sad. Since i cant ask her out on friday and she is not going to be her on thursday i need to make a decision by wednesday. wednesday is my last chance to ask her out and my question to you is that should i still ask her out wednesday or should i back out and forget about her? I never was this crazy about a girl and at first i knew that i like her, but now i know that i love her. (Note that today is tuesday )