I think it's a BIT overly charitable. At this point when Stella has crossed the line into wanting Stolas dead, I think that's pretty much the creator's way of telling us that she will function as a villain character. I mean sure, we can understand why she wants it, she is trapped in her royal lifestyle, and she thinks that Stolas's unwillingness to play along with this role is spoiling the royal prestige which they're supposed to be owed.
But I don't think that there is enough to work with there to make her sympathetic, given that she wants to have the father of her child murdered, so I don't think they're gonna bother trying making her such.
I was fully ready to see Stella get some more nuanced portrayal earlier on, but at this stage I don't think there would be much point to it, she has consistently been framed as the colder on of the parents, and whilst that doesn't prove much, it still shows the intention of the creators for her in the show.