Hi Amelia Maybe I'm out of place because I don't really know what you are experiencing but...
I find it very touching from your T, she really cares and in my opinion such humanity is at least good for the heart.
Concerning the urge of protecting her, no, you don't have to and it's not about being selfish, it's your therapy. I know I'm the one who wants to protect mine from the most stupid thing, but rationally I do agree that they don't need our preotection.
Instead of protecting her - which could be read as lack of trust/ fear of her reaction/ not feeling comfortable with her anymore - you could bring this up, maybe saying how you appreciated her kindness and how safe you feel with her (as far as I could understand from your posts) and then asking if she thinks she can stay now and in the future, and if she's not sure you might ask for suggestions or referrals, or someone that specializes and might be a secondary T and gradually stick, if you can and want to.
You and your therapist seem to have a great relationship and hopefully you'll have a productive and honest talk about it.

You know mine isn't trained for my issues but apart from the bad place I'm in at the moment, I wouldn't trade her with the world because... it's working. I mean: your therapist might be struggling as this is quite touching, but she might be ready to stick with you at the same time.
We're all different though and this was just my two cents...
A.