Trauma of any kind is very serious. This can be self-inflicted or inflicted. Both should be treated with extremely good therapists who specialize in trauma informed therapy. EMDR Certification is a key beginning when searching for a therapist and they should have many years of full-time practice as well.
There are therapeutic providers who only focus on blended family needs. [See referral process] [dealing with divorce], [balance relationships]
Providing the support that children need to build these [Executive Function] skills at home, in early care and education programs and in other settings they experience regularly, is one of society’s most important responsibilities. Growth-promoting environments provide children with “scaffolding” that helps them practice necessary skills before they must perform them alone. Adults can facilitate the development of a child’s executive function skills by establishing routines, modeling social behavior, and creating and maintaining supportive, reliable relationships. [developingchild.harvard.edu]