I feel like Ava would be very honest and forthcoming about the fact that xe’s more scared of Mia than Miranda
Like, Ava is very empathetic, has some experience studying psychology, is very perceptive, and is therefore very good at analyzing and predicting human behavior
So xe isn’t terribly scared of Miranda, because xe knows how to avoid her wrath (as well as how to earn her affection).
But with Mia, there’s just a layer of unpredictability/feralness (possibly remnants from her time with the Baker family) that sets off alarms in Ava’s head. Ava just ends up being very awkward and wary around her, much to Mia’s confusion. Like,
Ava, when asked about Mia: she knows no fear, she is fear itself
Mia, when asked about Ava: oh, the Dimitrescu butler? Kind of odd, I guess. Seems nice though :)