No she's not. The water is very unclean, super soapy, and she does it "to save water". There is often soap residue on the glasses and probably the dishes too, you can just see it easier on the glass. She wonders why she's had stomach issues most of her adult life.
This is also the woman who once let a turkey thaw in her fridge, which then leaked raw turkey juice (bloody water) onto a half slice of watermelon that was on the shelf below it. She then ate the watermelon after washing it off in the sink "because it was wrapped in plastic and was still ok." It was not ok, she got food poisoning.
I think she's just unhygienic and has an "I'm always right" Boomer mentality.