@Diane,
Absolutely re the not having to be family.....kids (or adults thinking back) recall teachers, the neighbour down the street, the grandmother they hardly saw, a relationship with a therapist that lasts two years or more is also very protective....sometimes healing comes from a loving adult relationship. I guess a kind of mantra I often use for carers is something like: "Damage from relationship trauma (eg poor attachment, neglect, abuse) can only be healed in relationship......."
And, to explain the terrible stuff very damaged kids put loving carers through: "Trauma experienced in relationship is triggered by relationship...and the closer they get to you, the more triggered they are."
It's kind of like dealing with combat related PTSD....have you seen the new technique they are using, with very realistic war computer scenarios, tailored to the particular triggers for the individual soldier? Sounds, images......(I guess smells would be hard...though they are often major triggers, as are temperature and touch)...
It has often been hard to trigger soldiers enough to get them to de-sensitize...(their avoidance strategies are so strong...and it isn't easy to re-create scenes of carnage) but this technique seems to be having some real success.
Erm but I'm rambling miles away from the topic.