What I am trying to say is why didn't Denise have a recurring friend. Theo, Vanessa, Rudy, they all had characters that were friends to them that made recurring appearances (Cockrouch, Kenny, etc.), Though Sandra also did not have a recurring friend but her character was already an adult when she became a regular so I don't really count her. The only friend of Denise I remember is the girl who got pregent in "The Shower" episode and that is only one episode.

And the high school friends in the "Home for the Weekend" episode were boring and unfunny. Denise's siblings friends were way funny then those people. The closest thing she got to a recurring friend where the characters from "A Different World".