Trusting my 9yo to shower and clean herself--by herself

It's 6:41 a.m. Just had my older daughter take her first before-school shower. She's 9, so it hasn't been that long since she graduated from baths, and as such she's not that learned or thorough in self-cleaning. But, she's definitely good enough, and where she needs to be.

So I get the water going for her, a nice warm temp, got the shower head adjusted so you get those warm, thicker jets in the middle, combined with the outer ring of smaller jets, of water, you silly, not actual fighter jets, jets is a word that loses meaning the more you say it, jet, jet, jets, jets, jet, and she gets in there and says she's fine so I leave the bathroom, go to the kitchen, and finish making my coffee. Didn't have any coffee yesterday; today's the day I treat myself to that sweet, sweet morning buzz.

It takes me all of 3 minutes. I come back to check on her. Water's off, she's out and drying off. 😂😆😂😆 Now I know she didn't fully clean herself! But she says she used conditioner, so I'm assuming she used shampoo beforehand. And I don't wanna ask, but now I gotta be like, "Lucy, did you clean your nether regions?" And I don't wanna be that guy! She's gonna remember me saying that as she gets older, it'll replay over and over in her head, and she'll start to despise me!

Actually it'll probably be something I say off the cuff sometime that I won't think twice about that she'll latch onto. I'll have no idea. ANYWAY

How do you handle letting your kids clean themselves? It's difficult for me to be the disciplinarian. I don't wanna be a buzzkill, or a bummer of a dad. I never want to make my girls mad. It's difficult for me to say those difficult things, like, "Why didn't you do this?" or whatever. Cuz when someone says that to me, esp a person like a manager, or someone who rules my life like a parent does, I immediately feel more guilt that I oughtta. But I don't want to be super nice and forgiving of bad stuff, cuz that doesn't give the world responsible people coming out of my household when they're old enough to set out on their own. We gotta teach our kids to do stuff for themselves, but it takes discipline along the way--from us, and them.

Photo from 5 seconds ago. note the wet hair on the kid on the left. Note also two instances of Creepers.