Is queen fairy Teresa o not?

Probably no. Her archetype is like on Aunt Elisabeth/ Azura/ Enchatress- magical (or not so) helper of protagonist. In cisne Lake, probably only Barbie, as Odette, and Summer as Marie (but, in 2003, when cisne lake was came out, isn't Summer, lol).
Also, I think, that in old classical cine from Barbie's friends was only she herself. Teresa, Summer and Nikki appears later, in Diamond castle, navidad carol & Three musketeers.