I think that's a good move.

(I'm going to draw an analogy here; I am in no way saying you are in love with your therapist). Think of this a bit like the "in love" sensation of starting a new relationship: you are all excited and can't see that person's flaws yet and are all head-over-heels. You have that gushy, sloppy-happy, all-is-right-with-the-world feeling about that person. You are floating on the proverbial cloud nine. But that is not "love"; that's "in love". And there is a HUGE difference between the two. "Love" takes time and only comes from knowing the person's quirks and flaws; it comes from experiencing good and bad and highs and lows and successes and failures, and still knowing that person is important and worthy of respect despite whatever you experience together.

Let this therapy with this therapist settle in. She sounds great and probably will be, but take a breath and try to keep your feet on the ground. I like your idea of writing out your experience of her and just hanging onto it. Some people keep just a therapy journal, focused on their therapy journey, and separate from any other kind of journaling they do. It might be a good idea because it is a physical "space" and reminder that the therapist and therapy are contained somewhat, separate from the rest of our life. It also might help you get past that impulse to "tell her now" what you are feeling and thinking when those are thoughts and feelings that are more appropriate for discussion in session.

Therapists talk about compartmentalizing being really important for their own effectiveness and their own well-being. Personally, I think that idea of compartmentalizing therapy somewhat from the rest of our personal lives is not a terribly bad idea. It's easy to fall into a pattern of our therapy becoming enmeshed with our entire being, and that can end up badly for some. Realizing different areas of our lives can be kept separate from each other (and often are better that way), can actually really simplify life and feel more settled.

I'm so happy for you that you were able to find a therapist that feels right for you. I knew from the first sessions with my therapists when they were going to work well for me, so I understand that experience. Just slow yourself down a bit and let things happen a session at a time.