Rescued kitten has no fear of our dog

I discovered that a kitten was going into the possum den under our shed in December. Posted on lost pets, a woman reached out offering to help trap it, after he was successfully trapped she said that she couldn’t take him. So now we have a kitten. We have gotten neutered, chipped and up to date on shots. Slow introduction to our 2 small dogs. He’s been with us about 9 weeks now.

He gets along great with one dog, they chase each other and play, will sleep pretty close together. The other dog is very fear reactive, nervous (she barks and snaps at my husband- only at night) and all around nuts. She is curious about the cat, will sniff him and stuff but the kitty tries to play with her like he does with the other dog and she instantly pins him down, is growling and snapping. She hasn’t actually bit him but her reaction seems more reactive than playful so we keep them separated for the most part, supervise closely when they’re together and have a muzzle on the dog for short periods of time.

The reason I’m posting is because the kitty seems clueless about the dog threat, I had to pull the dog away from the kitten because kitty was attacking the friendly dog from under the bed and the not friendly dog walked by so he did the same thing to her and she immediately pinned him, snarling, snapping. I pulled her off of him and she ran to “her” room where she sleeps - and the kitten immediately followed her in there. It’s like he doesn’t have a sense of self preservation, he isn’t cautious or tentative around her at all. I’m guessing the best I can do is what we’ve been doing but I was wondering if this is normal? Shouldn’t he be just a bit scared or leery of her?