I don't think it's the maid, she doesn't have evil vibes
The queen though there was that bit earlier?? Oh wait I think she's dead
But I don't understand why there's a part in the intro about her relationship with the husband needs fixing that's suspicious too but not as the suspect, I think he actually loves her
What about the other madam- the red haired one, or maybe her daughter. The timing of her death with vicente's coming of age is also sus