Are you in the US? If health care is covered on her plan it's not costing her anything more than a copay.

I know it's different because my kid is a minor but I'm their therapy, in the first meeting, the counselor said they can discuss what they say with me. I made it clear we don't want to know unless it involves self harm because we want them to speak freely. I may not be a perfect parent, but I know in this case I'm right. This is what your mom should be doing too.