It turns out that Vicky is not the problem at all.
DD#1 told me that Vicky paid the rent for Sept. 1st a few days earlier, even though it was DD#1's turn to pay. It turns out that Vicky decided to be the rent payer, which is fine, but Vicky should have told both DD#1 and Laura that this would be the case.
DD#1 said that Vicky didn't even ask for money from her or Laura. I told DD#1 that Vicky shouldn't have to ask for money, you should just make sure that Vicky has your share of the rent before the first of the month.
Well, obviously Laura is in the wrong, but this part stood out to me. I don't think your daughter did anything wrong by not giving money to Vicky several days before the first of the month. Daughter thought she was the one who would physically turn in the rent that month, and so of course she hung on to her money and waited for the other women to bring theirs to her, since Vicky didn't communicate the change in plans. And it was still a few days before the due date, too.
I think that's a case of everyone dropping the ball on communication. I think the awkwardness over the payment split put them all in a zone where they weren't talking out the details of paying as freely as they should have. Everyone should have known which one of them was going to make the ultimate payment, and that person, whoever they ended up being, should never have to ask for the money, it should be given at an agreed upon time.