I'd let it drop. This is the T who terminated you and didn't want to see you anymore. I remember you described some things that sounded kind of scary/creepy to me, so I don't think you should contact her about this--might come across as stalkerish. I think it's better to let sleeping dogs lie. She didn't want contact--respect that. If you feel guilty, you could donate to a charity you think she'd like, and dedicate your donation to "my therapist." My guess is that therapists are used to not being able to collect from clients from time to time. (She may have been able to write it off as a business loss if she has her own practice.) I agree it might be good to discuss this with your current therapist--someone who knows your story--to get an objective viewpoint.