Kara did have one big advantage over the other new slayers: Her father, a former teacher, not only supported her once he found out, but actually came along with her and became a teacher for all the young slayers. But I think that sense of community is a big factor in why the slayers in my universe are relatively happy with their lot -- there's something to be said for being in a group, rather than a lone warrior with the odd always stacked against you.

Overall, I suspect some of the new slayers are better off than they were before, and some worse off ... which doesn't take away the question of whether the spell should have been cast against their will, of course.