I came across Adopting the Older Child, a terrific blog from Robin Hayes, a psychologist and the mother of three children, two of whom were adopted at around four years old.
In a post on helping new siblings learn to get along, she outlines steps in a program to make sure that they have time to get used to each other and accept each other, without beginning to re-enact abuse or trauma.
For example, as the kids get used to each other, she advises:
Over time, build on success. Slowly extend the allotted time for play. When they can play successfully for about 20 minutes one-on-one, add one 10 minute session where all the children play together, supervised by an engaged, involved parent. Again, keep it positive and end on a happy note.
In the past, adoptive parents were often not given much information about attachment and behavior issues that children might suffer from, let alone clear directions on how to deal with them.
Robin is a heroine to me for welcoming into her family older, hard-to-place kids. I always thought that if the time came for me to have kids, I would adopt one with medical problems; that as a society, we should only adopt until all the orphanages were empty. (The time to have a family never came for me.) But Robin is doing it.