She chose to be with him at start now because of her children she has decided leave him because everything that happened but i don't think Tara would shoot Jax she more controlled than that but thinking this is what Gemma would do was rather amusing consider she was using Gamma as her role model.
I think your right she still in love with him which suggest she has some right to be angry i just assumed because she wanted a divorce she wouldn't care what Jax did?. The fact she been through all of that and they were still together was amazing i really didn't think Tara would gone as far as she did if she had no choice.
I really hope she doesn't turn into a rat because the ending can implies she would