Hi java478,
I wanted to join wendydarling in saying hello
It's wonderful that you were able to find a therapist trained in DBT skills.
My experience is that you can have good and bad therapists, but it's not necessarily about how long they've been practicing.
Do you know if the individual therapist has a group she turns to for advising? The counselor that my SD20 saw for many years was trained in DBT, and apparently she (the T) met with a group of both junior and senior counselors, to get support following DBT practices with clients.
I wonder if the T you are thinking about has a group like that?