My resident cat is still growling at the new kitten but also slow blinking at her

A couple of days ago I bought home a new kitten, Willow, to my resident cat, Nera. Nera was pissed off initially but now I’m confused on where Nera is at with the kitten.

I have been keeping Willow and Nera separate with Willow staying in my bathroom. At first Nera wouldn’t go anywhere near the door and refused to even get close to me if I smelt like the kitten. Now whenever the kitten meows Nera will run up to the door and just sit in front of it. This morning she even pawed at the door and when I went in to check on Willow, Nera was sticking her paws under the door, letting the kitten play with her.

Here’s where I am a bit confused: During supervised time, Nera wants to sit and watch the kitten from a distance (no aeroplane ears, crouching or tail swishing). She will even lay or sit near Willow and slow blink at her. However, sometimes Nera will run up to Willow and growl (no swatting or hissing) before going to a spot where she can still observe the kitten.

Even as I’m writing this, Nera is loafing in the doorway with her tail out while watching the kitten who’s asleep on my bed.

What does this mean???