I also doubt that Rukia is a Vice-Captain... in fact, I think she is far from it...
But... ZhanZhao... you are talking about Rukia who got her powers sucked by Ichigo... not a Rukia who was full-power in Soul Society previously, so your statement is irrelevant to the what is being discussed...
Edit: Or is it ever mentioned that she never knew the name of her soul slayer?