Between her being decidedly "not culturally elven," caring about the concerns of "the common/poor people in general" but not elves, her being very anti-nature, having a much fuller face than the average angular elves and now much taller than elves, I wonder if her shtick is going to be that she's elf in genetics only. She has pointed ears, and that's it. Everything else about her, from her height to her features to her background to her values and goals are going to be deliberately anti-elf in every way.
Gee BioWare, haven't seen that before. A city elven companion that not only feels no kinship to city elf culture, but doesn't feel attached to or care about other elves in general? Zevran of the Antivan Crows and Fenris the Tevinter Slave, both of whom takes shots at the Alienage and Dalish Camp, feel no kinship to other elves, and claim everyone has problems / other people have it worse, so why care about these people in particular. Yeah, never seen any of that in a city elven companion. Sera is going to be new, different, and unique in that respect.
She and my Dalish Inquisitor are going to have a lot of common ground, I just know it.
Being a city elf doesn't make one "deliberately anti-elf." Caring about common people and caring about elves aren't mutually exclusive.
Zevran pleads for the lives of the clan in Origins if the Warden goes elven-cidal. Given his general apathy about death, this seems significant to me. His Dalish heritage is clearly important to him even though he doesn't consider himself one. In DA2, a Dalish clan is happy to provide him refuge. It's not fair to say that Zevran doesn't care about other elves.
As for Sera, she "revels in the athleticism of being an elf, of being different." So, it's not as if being an elf doesn't matter to her at all. She also likes to make friends; friends are better than power. She'd probably be open to finding allies among the Dalish, provided they don't dismiss her out of hand for not being elven enough for their tastes.