No lorelai (the mum ) only has the one child - another baby for Bex would defo ruin that fantasy she has made for herself. Rory (the daughter) does end up with a half sister which I could totally see happening for Nina.
There is absolutely no way that sedentary Becky who drives absolutely everywhere is going to wash her own windows. Unless she is absolutely desperate for contentWhy doesn’t she just ask on the local Facebook group for a window cleaner? Isn’t that what we all do these days?