Last week made sense to send home Jason if you were in Vanessa's shoes. Liz is the pivot of two votes. She has Austin and she has her sister. She didn't want Austin to go home. So now Vanessa has Austin and the twins on her side, as well as her side thing with Steve. If veto is not used, then one of Clay or Shelli are going home, and the other will be gunning for the other side. So that's another possible vote. That leaves JMac and Becky as floaters, with the other side being James, Jackie, and Meg. James can't win HoH, so after Thursday's eviction, that would be time to gun for him if you're on Vanessa's side and win HoH. Put up James and Meg. Worst case scenario is Jackie wins veto and has to choose one to pull down. You should still have the votes to take down the other.
If either Jackie or Meg win, they should put up Vanessa and whoever survives this next vote(Clay/Shelli). It's the same thought process used to eliminate Jason. Strike off the head. Most think the twins an obvious target, but if I were playing, I'd save them until after I eliminated more strategic targets.
FTR, my favorite character is JMac, but I like to see the different sides of the house play strategically more than I root for a particular player.