Personally, I don't remember anything that shows that she put them actually under control (for what it seems explained, kins should follow orders unquestionably, and having reduced free will at minimum, something we don't see on anyone).
Check out ch.8 p.6, for example. If you keep reading from there you even get Wakana "explaining" how Ruruna is a "great hypnotist" (her attempt at pointing out how she's got power over her kin). Ch.9 shows why it doesn't always feel as conclusive: it's kinda the monkey's paw problem. Rururuna orders something like "let me suck your blood" and because it's not so precise Yura practically undresses. The problem isn't that she can't order them around, the problem is that her general orders are open to interpretation and her kin do act within that.
Teacher's chapters (around 14-16) are pretty conclusive to me too.
Yeah, you can invent any sort of explanation - that they are ALL just randomly going along with her ALL the time. It's fiction after all. Maybe it's just a collective delusion, or whatever. BUT. There's zero indication that that is true. People question whether Rurururuna's control is true because it's not always obvious, but the opposite has absolutely no basis in what's being shown in the manga whatsoever. Her commands never fail. There's never any outsider who doesn't see what's happening, or that indicates a crack in what we are being shown or told.
As for "kin having reduced free will" - that's just your own rule. Nowhere in the setting does it claim it works like that. They just can't go against her orders and they
never do, and they have to do what they explicitly are being told and they
always do that.
