^Playing the world's tiniest violin, here.
I don't think you should beat yourself up about this. Yeah it was childish and petty but you know that and so does everyone else that acts that way, especially in creative fields where everyone's fighting over a small window of opportunity. I'm sure this girl acted the same way before her flick got distribution and she knows people are talking that way about her now. If we were all mature and socially adjusted we would be doing something else for a living, right?
(By the way, is it Lena Dunham?)
Edit: Seriously, can we not get some fucking capitalization in here?