I found cognitive behavioural therapy VERY helpful. Other C's or T's seemed to wallow in the how I got to the point I was at and kept going over old ground. I needed to recognise when my thought processes were unhealthy, when they weren't ....and what to do about them. I needed to move on and have coping strategies. CBT has given me that - I really can't rave about it enough. Those two books I mentioned are good, although not the easiest reads....and one really needs to be seeing a good CBT therapist to reinforce what you learn from your reading.
A lot of therapists get wrapped up in FOO, (Family of Origin) issues, and that doesn't suit a lot of people - your S sounds like a person that needs to not get wrapped up in FoOO issues from how you have described her and she sounds like she needs to develop good coping strategies.
CBT taught me how to deal with the things I can handle and how to compartmentalise away the things I can't, (until a time that I CAN do something about them - if ever), instead of just running around like a headless chicken worrying all the time but achieving nothing. It even taught me when to communicate to my H that I don't want to communicate for a while and just need some time out to get my head together - if that makes sense? Him knowing that helps him know how to deal with me instead of him stressing as well and then increasing the pressure load on me.
Saffie me 46 H 46 M in 1986 D20,D18,S16,D13 H's A 01/05 to 07/06 H recommitted to M 07/06 renewed vows 09/06 Going from strength to strength