Hi, Leora:
Several schools in Washington State that use PBIS have incorporated trauma-informed practices. It's a good fit. Here are links to a couple of stories:
There's no such thing as a bad kid in these Spokane, WA, trauma-informed elementary schools -- Spokane, WA
Q-and-A with Suzanne Savall, principal of trauma-informed elementary school in Spokane, WA -- Spokane, WA
What a trauma-informed approach provides that PBIS and restorative justice/practices usually don't is the attention paid to vicarious trauma of teachers & staff, to how their own behavior can contribute to inadvertently triggering a student, as well as to students whose response to trauma is to withdraw instead of act out. There's also more awareness of looking at all school policies through a trauma-informed lens, which PBIS and restorative justice/practice usually don't do.
Cheers, Jane