To be honest, I fell in love with LFB from the minute I saw her in Twin Peaks, not only with her youth, her blue eyes and her girl-next-door vulnerability, but with how she injected so much emotion and warmth into her character, something especially rare in such a young actress. Her roles in future films did prove she was a capable actress, and more so an actress of character, specially when she got to play difficult, vicious and/or bitter women, a character prototype she's proven to do quite well. The problem is that, just as you say, there's much of the diva in her to actually go back and accept her status as part of the Twin Peaks phenomenon. You can't deny that she has talent and that she actually made the Donna we all got to know and love, but maybe Lara has never been able to stand that there are very few actors in Twin Peaks that could manage to become big Hollywood stars, a general trend for most of the cast. Maybe she just can't deal with that and wants to leave this part of her acting career as far in the past as possible, even with all that she loved being in the show. So there's talent, but too much ambition.
PD: Plus, if she's just content to be a great acress, why the anorexia and the senseless plastic surgeries???