Below is a list of Ontario professionals, organized by geographical region, who have completed the ACO's eight-day comprehensive training program, ACT: an Adoption and Permanency Curriculum for Child Welfare and Mental Health Professionals. Taking the ACT training in and of itself does not guarantee a professional is adoption competent and ACO is not certifying the professionals listed below as such. However, the ACT training is an intensive training program that provides an excellent framework for professional working with all members of the adoption constellation.
In addition, you may wish to consider feedback/recommendations of other families, and ultimately your sense of whether you and the therapist under consideration can work well together.
Here is a link to an excellent resource, Selecting and Working with a Therapist Skilled in Adoption, prepared by the US Child Welfare Information Gateway to assist you in this endeavour: https://www.childwelfare.gov/pubPDFs/f_therapist.pdf. The publication outlines very good guidance and questions to ask of a professional you are considering working with.
Ultimately selecting the right professional to work with your family is a personal decision.