Comparisons are tricky things.
You know your therapist, so you know her good qualities.
The new woman is someone you met and have an impression of, but you don't know. You enjoyed the interaction that you had with her then, which wasn't therapy so it may not be reflective of what therapy with her might be like.
So you are comparing a solid known with an impression and what you have added to that impression (what therapy might be like with her).

You could schedule an appointment with her and talk about this with her. You can also talk to your therapist about this experience to let her know more about you and what you want. Could it be that she could provide this for you, I wonder.