I love how in touch with her emotional state and how connected to the importance of this you are. That is such a huge asset for her. You really get it.
Trust in a therapist relationship is earned. A good therapist builds the relationship and will be adept at hearing threads of what she is avoiding. Many people feel huge relief at finally being heard and seen for the first time by someone else in a way they never have.
This is such a wonderful opportunity to build self-protection skills for relationships at 13! So many serious life mistakes could be avoided by what she learns here. I hope you find what you need and update us when you know more.