No defense for Gene, havn't seen enough of the show to see him ever be anything more than a 2d bad joke.
Louise (fuck the spelling) on the other hand is more or less perfect beyond the voice which yes, no little girl should -ever- sound like her. If they did, bring them to a fucking hospital. That being said, her articulation of words is on point for a 9 year old, nothing odd. Her articulation of feelings is odd because she rarely acts human. This is ok though, considering Bob. Because when you look at it she is just an aggressive version of Bob.
Children can be very witty, they can have vast vocabularies and often find themselves in situations where they get beat for it. Louise is in the opposite situation. She has next to no maintained boundaries, no maintained schedule, no normality in her life. For a 9 year old that's a pretty big deal. Acting out is how most kids cope with a lack of supervision and structure. She acts out almost every episode. The way she acts out is exactly how her father does, just swapping the passive and uncaring tone of Bob with the aggressive and demeaning tone of herself.
Take the B&B episode for example. Teddy moves into her room and moves her stuff. Her response is to start yelling and she tells Teddy she will see him in hell. No human being would say this, or act as she does. Any normal 9 year old would simply pout and cry. But she has learned from her father that blank statement yelling is how you act when upset. So that is exactly what she does.
Children copy the phrases, mannerisms, and moralities of their guardians until puberty almost to a fault. For Louise to copy Bob's reactions like that is only normal. Even if it seems odd for her to act how she does, it is only because she has no other frame of reference. This makes her "act" older than she is, but really, it is her miming how to be upset. Because really, who else close to her gets close to upset in the show?