AFAIK the only things available with Vickie currently are:
-have her "liven up the party" (she has a menu for multiple characters, but I think only Ashley is available at the moment)
-fool with her in the hot tub outside, she will test you on how long you can last, and you can increase this by practicing with other chicks or drinking some booze
I believe these are the actions the walkthrough mentions. I also remember reading somewhere that the whole array of Vickie quests is still under development.