I seem to piss her off in the Elven Ruins. I do not have unlock cantrap and very little lock pick exp. So I go to bash open the barrel in the south passage and she gets mad tries to leave and everyone else jumps her. Any suggestions???
Nope everything was fine and I also chose to smash the barrel. Try telling her to way some distance away perhaps, then smash and get her back.
It could be that her alignment towards good causes her to to not like your stealing the headstone, joining the thieves underground, etc, but why she would go beserk over attacking a barrel is beyond me. Load and see if it happens again. And just as rule before you do anything evil or dark, etc. make sure your "good" followers don't witness it and are waiting a good distance away. You can defeat that by having 20 charisma-it ensures 100% follower loyalty, and even if they verbally object to your acts, there reaction to you should not change nor will they leave you.
I ahd the same problem with Raven. came back from half ogre island killed the gnome in tyrion's house she objected attacked me and got killed. that was ok she never cast any spells in combat.