Whoa, that's what is bothering you ? Try to put her out of ecuation and like the movie without any problem. I had to deal with more than 23 people from college or FB or instant messaging about how they did not like AVATAR and I was just "Aham... wtv" because most of the opinions were unfounded and just throwed to get some attention or sort of something...

If she thought the movie wasn't to be liked maybe she just WATCHED and period. It's a difference between WATCHing and SEEing the message of a movie, between talking a**crack to take attention and to say something based on something that you support and think is constructive.
True friends... C'mon. I had this discussion today twice with some friends of mine. It's hard to find a TRUE friend because most of them are TRUE when you help them and FAKE when you need them. And that's all there is to it... Sorry to hear about... that, it's not your fault.