Definitely not right from the first session. While I had respect for her obvious competence from the get go, it took a while for me to warm up to her in a personal way. It's been painstakingly gradual, really, but I can think of a pivotal point.
When I was a teenager and struggling to articulate to her what I thought about the possibility of a god, and she said, "...Have you ever read Plato?"

I had not. She proceeded to explain platonic theory to me. She used a dog in an example of a form:
"Now... imagine there is a dog. That is the doggest of all dogs."
"The absolute dog?"
"The absolute dog."

The hint of playfulness in the example was what did it.