Well, as of today, in America at least, she's started talking about the fashions, so I'm not really drawn to liking her as much as I am disliking her. Which is a shame because she could have been really interesting if she took a chance with Rhyhorn racing. But of course, she just wants to act like a girl. I was happy that at the end she seemed to consider the possibility of battling and Fennekin has so far not disappointed in that aspect for a grand total of twice, so I hope she'll at least keep that in mind.
Her crush on Ash is cute and all, but if that's all her "gimmick" is, then...it'll get old fast, especially since Ash is so oblivious to it. I mean, her entire purpose of leaving home, in her own words, was to return Ash's handkerchief and to see him again. Then she wanted to impress him with her outfit and made him cookies. I can do with the shipping and find it adorable, but if it becomes too forced and the soul of Serena's existence on the show, then...that ain't good.
My opinion of her may change as we get more into the series and she discovers what she wants to do, but at this point, even her Fennekin seems more interesting than her and it never does anything.