Becca is not shocked that abbey is a whore. Becca encourages abbey to get drunk, despite she has had enough to drink but abbey like the obedient slut obeys and drinks and then launches herself at Becca's boobs...Becca knew full well what was going to happen...it seems to be full of very unlikeable women so far--i just hope we are going to see a change around very soon with these girls.
I would say that this description of Abby does go a bit far. Where I agree: The alcohol disinhibits her quite a bit and she's a lightweight when it comes to drinking.
I think the situation where she grabs Becca had the thought process of "oh, there's my stepsister I'm going messing with." In the long history of alcohol, Abby is certainly not the first person to have had such and more foolish ideas. I think that the fact that Abby has always been treated very much like a raw egg by Frank, Lilith and Becca so far means that she lacks the experience that decisions made under the influence of alcohol can have serious consequences. Becca said it herself in the scene: If it hadn't been for Abby, she would have caught one. I think a slightly chilling consequence that goes beyond embarrassment is definitely needed to make her reconsider her drinking habits. Or diabetes. Then she can say goodbye to alcohol, too.
I see the responsibility here, at least from the second time on, more with Frank: He knows by now that Abby is a lightweight and still doesn't manage to prevent Abby from getting drunk.
Apart from the drinking behavior and the handling of alcohol, however, I think the ladies are okay:
Becca is definitely manipulative and pursues her own plans but in the long run they are also for the good of Frank, Abby and Lilli, as you can see with the judge during the divorce. She definitely cares about the welfare of the three.
Abby, for one, is essential to Lilli's character development and one of the few who can calm an angry Lilli. In addition, she will also go through a certain amount of character development through a certain encounter.
Lilli is known to have a bunch of problems of an emotional nature and therefore has the greatest amount of character development ahead of her, but you start to see this in 0.11, 0.12 and Lilith's Longing.