Hot take: seeing Stella in this episode as a petty idiot explains her character and... that's not bad? Not every female villain needs to be a "boss-ass bitch" with genius plans. I kind of like seeing her being an evil dumb cunt who was likely married off to Stolas to secure bloodlines/an heir (that lines up all too well with traditional aristocratic tendencies tbh). As long as they make Andrealphus and that family's plans clear, this can work...
...which is kind of a big IF honestly, but I'm cautiously optimistic. Also, he was barely in the episode but the skeevyness of Andrealphus was great and I want to see more.
the problem is the inconsistent characterization she has, in her first scenes she was portrayed as an angry wife because of the humiliation of being cheated, worried how the other Goetias will react and how Stolas' actions are ruining the family name, she knows the consequences and prioritizes her public image, even the connection and contract with Striker was done without the public suspecting or relating her to the attack.
and the fact that Octavia still spends time with her and blames Stolas for the fights indicates that she is very good at hiding her behavior even indoors, which would require restraint, intelligence, and manipulative ability since Stolas is much stronger than her and he could just react to the abuse but she keeps him under control and weak in her presence
in episode 1 S2 the discussion she has with Stolas she keeps herself controlled and restrained even with his defiance and reminds him again of the consequences of his actions, the reaction of the Goetias and talks about how she wants to torment him, do you think that someone who values so much her status wouldn't know that all Stolas' assets would go to Octavia and she would be left with nothing?
the problem is not "female villain can't be stupid" and Stela is not a genius either but she is not at that level of stupidity of sabotaging her ambitions because she just wants to kill him so much that she makes such a public attack on Stolas, with her at the crime scene and needs Andrealphus to remind her of her own plan. She was lucky Striker hadn't killed Stolas when she called or he'd picked up the phone at that moment in the first place.
Stella's characterization at this point in the show changes to fit the idea of the day and not align with her previous actions. it will be difficult to have her perspective on this conflict that is not one-dimensional, even the presence and influence of the other Goetias and their reaction in this situation is vague, if this were to be a drama of noble families their opinion and actions would be more impactful, which would help fleshing out her motivations in the form of pressure.