Sorry if this seems a little mean, but for those of you that think she seems fake, I don't think you have gotten the entertainment business at all or have a rather "immature" / naive view on how we are as people in the world and especially how music and public image corresponds with our private selves. This has nothing to do with whether you like her music, style or her public pesona at all, but the part of her being "fake".
I'm not a fan of avril's music in general. She had some ok songs, but I never gotten into her albums.
When she first started out with the hit complicated, she was never really a punk artist in the historical sense of the word. Yes, the song had more elguitars than the slightly rnb-ish pop of christina aguilera and the pure swedish produced pop of britney spears(which had none) , but avril's music was from the beginning packaged as pop. Her image was maybe more "badass"and she made that mainstream, but just as trends change and we no longer wear puy hair the 80s way, this happens all the time. How something looses credibility (or becomes too forced) just because it spawns a mainstream trend is beyond me especially when the artist is packaged as a pop (ular) artist to begin with.
As for her not staying true to her initial image? Well, being a pop artist your role is to entertain first and foremost. That being said, these celebrities are just ike us in the way that they want to try new things and that they CHANGE as a person. Her working for Chanel, one of the famous fashion houses, with the above in mind, is it really that surprising, and in what way is she really betraying herself? She's obiously interested in fashion and style and that goes very well with working for one of the biggest companies providing "style" to the public.
I don't understand why singers in particular always have to be faced with accusations of not being "real" when people gladly accept actors in roles they have nothing in common with. It's not that different. If Angelina Jolie can portray a crazy person in Girl interrupted and do a really good and convincing job, why cannot a married avril be mad about her former boyfriend similarly? (I'm not saying she does, but that is beside the point and judging from her popularity she does). In the end both the mainstream actress and the pop songstress do a job, work keeping people entertained.
Another interesting note is that she's probably one of the most famous western artists really nailing the "japanese" style with the blend of cute and pop rock, reflected by her strong album sales. THe best damn thing was the fourth most sold album in 2007 selling 848,912 copies. The second most selling western artist was Linkin park at 27th with 362,773 copies sold.