Eventually, she probably will want her hair pressed with a hot comb or relaxed. Obviously, you don't have to give in and do either one, but the older your girls get, the more kids they'll run into w/relaxed or pressed hair and the harder it is to convince them that they don't want what they want.
My sister used to run around talking about how she wanted her hair to be "blond" and by that she meant straight and flat, not yellow. During that time we also lived in a predominantly cc community. My sister was/is a very sensitive person and wanted very much to fit in. To this day she wears a weave and keeps her hair light in color. I don't recall ever having those feelings, but then again, I grew up around more aa people, people who wore their hair in all sorts of natural and relaxed styles.
I say this to say that social acceptance is often more important to kids than the long-term health of their hair and there's nothing you can do about that. IMO, fighting it just creates more self-esteem issues. If you can swing it, try to find more aa hair role-models for dd or allow her to have it pressed for special occasions. That might at least offset some of the pressure she feels to conform.