Considering Cagliostro's backstory is making herself a female body, and shoving her soul into it, and she's offered to do the same as a "hey we're friends want me to make you a cute body? ♡" To two characters (and later threatened one of them with the same) this is totally reasonable.
Honestly the only questionable thing about it is the fact Cagliostro's spitting out coffee at the request
Every school morals person who appears in manga makes me bewildered because who would actually be so busybody as to want annoy people over that stuff
I was kinda like that in highschool. Overzealous about rules that were honestly entirely idiotic. In hindsight it was really dumb but I had a really black and white view of things and "Obviously it's important to follow the rules!"