I've not heard tutting called clucking before, that's a good way of putting it. This is such a good read. 

>“Your wish is my command,” he often said, as he wrote a check, or offered his credit card number for anything they might desire. “As long as my girls are happy.”

That was the moment it changed, and I just felt immensely for Katrina. I knew a girl very like her, her dad never home, her mum investing her whole world in her daughter, taking her on expense trips, her dad buying her happiness. It didn't make her this level of entitled, although she did have a look, a horrible twisted look somewhere between disdain, pity and curiosity, that evoked a similar response from other kids. For a long time she kept any possible friends at a distance, and in this I can get an idea of why. It's a strange oxymoron of self-importance and low self worth, very well captured by the mum's solution of buying her daughter friends. Angela's steady remarking on Katrina's "clucking" almost underlines it being allowed to continue. 

This would make a wonderful graph lol, at first it's easy to feel for the mum, and not for her daughter, but then the story progresses, and it's just as easy to see it's more complicated than that

>But Katrina clucked, so Isabelle took the sofa bed.

it begins to drift with Angela, where the mum seems more culpable, Angela providing a normal touch point to contrast the other to, until by the end, you just sort of feel for all of them. I do really like the twist you have gone for, a good read, fitting all aspects of the prompt yet still not playing them off in any sort of predictable way.