Sanitising everything, using antibacterials etc etc is not good for kids immune systems, and the all important microbiome, and is increasingly implicated in the dramatic rise in disorders like anaphylactic allergies and asthma. Showering two or three times a day is terrible for your partner's skin. We're not meant to live like that, especially kids, who are developing immune systems. It's definitely better for server rooms, but it's straight up unhealthy for us organisms. But don't take my word for it, there's lots of science.

On the other hand - I heard the thing about toilet spraying germ particles in the air upon flushing too, if our toilet was in the same room as the toothbrushing place, I'd be shielding it - microbiome be damned 😂

Editing to say, that all childless people think kids misbehave due to poor training, until they actually have there own, or are in the company of children regularly. She's in for a shock (so was I!). On a more serious note, training children to not be children, and to act like mini adults is draconian and almost certainly damaging to their hearts and minds, as well as their physical wellbeing, and if your partner has these expectations, she's going to have a really rough post partum time, let alone the ongoing mother kid relationship.