Also while I'm on the topic of horrible adults in Chloe's life, can I talk about Joyce for a second?
Her behaviour in BTS is more tolerable. It's before David has officially moved in. She really likes him. She's hopeful that David and Chloe will be able to iron things out. As far as she's aware, he hasn't done anything particularly bad except be argumentative with Chloe, which given who Chloe is, that can be understandable from an outside perspective. Agreeing with David to have Chloe empty out her pockets is a bit much, but I can understand where she's coming from to an extent. If David searches Chloe's room she actually defends Chloe. If Chloe regects David and he gets aggressive she tries to put herself between them.
BTS Joyce isn't a complete self-centered doormat, even if she's heavily flawed.
In LiS season 1, however? Honestly, fuck her.
She doesn't care about David's behaviour unless it directly affects her, Chloe be damned. If he slaps Chloe in Episode 01 (and there's not one but two ways this can happen), she'll spend her scene in Episode 02 vaguely claiming that David will be "punished," and then immediately backtracks and tries to justify his abusive behaviour towards her own daughter. Having your s/o hit your child for anything other than self defense (as in the child trying to physically harm the s/o with a weapon or some such) should be immediate grounds for breaking up and cutting ties with that person. Instead she stands there and more or less victim blames Chloe to Max's face.
Max (if she made herself visible to David but didn't take the blame for the joint): Joyce, he slapped Chloe yesterday
Joyce (immediately starting her bullshit): He feels awful... and he will be punished. But Chloe does push David, and it's not fair.
Joyce (as if the next bit justifies domestic abuse): He paid his dues in a war.
Joyce: He does care about her, along with all the students at Blackwell.
Max: That's no excuse to hit a girl. He's an adult.
She's quick to claim after this that David promised it would never happen again (never mind it shouldn't have happened to begin with) and tries to garner sympathy from Max because she wants "the three of them to become a family." BTS only makes this worse in hindsight, given the aforementioned scene where I mentioned he can get aggressive with her. This means she potentially knows it's a pattern, but acts entirely unconcerned.
The second she finds out David has put up security cameras in their house and has files on Kate and Rachel? That makes her uncomfortable, and thus that's the crossed line that causes her the break up with him. It's about her and her comfort level. Apparently Chloe getting hit is within that comfort level.
Oh, and after she's kicked David out and Chloe sarcastically says "have a nice day," how does she respond?
Joyce: Chloe, for once... just please shut up.
I like to think she started out as an OK, if not a good, mother, but by the time of LiS season 01 she's an abuse apologist and can go fuck herself.
