People who belittle other people's work are just being cruel and spiteful. It's most likely that that nasty girl actually thought your work was better than hers and felt the need to put your work down to build her own up. Oh, and another thing, it's the finished product that counts, not what software you used to create it.
So @Sakura,believe @Zeref, @Forlorn and myself when we say that you're a very talented graphics creator.