Ventress is a complete anachronism at this point. With Dooku, Palps, and Anakin in the on-deck circle, there is no room for any more Sith. Rule of 2 and all that. Hope they give her a fitting exit this season.
Well, she chooses to "disappear" from the entire war eventually, but that's not until "Star Wars: Obsession" issue #5:
This comic was actually (story-wise) supposed to take place before the entire TCW cartoon series, which means that Asajj shouldn't even be in the TCW series at all, because in this comic she plays dead for the remainder of the war after Dooku abandons her. But she's never actually killed off.
And also, she's not actually Dooku's apprentice, more instead his acolyte. He uses her to carry out all his dirty work - like Mara Jade carried out the Emperor's work. But he makes it clear in the original CW microseries that she's not actually a Sith, but she really wants to be one.