She is sitting in the library, studying. It's her most common pastime, by hours; spending time with her sister is more enjoyable but Jaromira prefers to socialize more broadly and Katarzyna would only get in the way. This is better on net; the two of them share a room, so it isn't as though her sister's time is entirely hogged by the other girls who call this boarding school "home." Or at least "prison." Katarzyna doesn't mind it, though; the school library is excellent, and basic manners and care for the books has endeared her to the librarian to a sufficient degree to lubricate the interlibrary loans process when there's something she wants to read that they don't have.
Kanimir and Jaromira in Fabulous
She looks up what local hospitals participate in magical girl related programs. Once she's filled out the oodles of paperwork where does she drop it off or mail it to or whatever.
She hisses something uncomplimentary under her breath and makes a note to ask at the hospital.
The next day as soon as she can manage to get away she wings over to the nearest hospital on her list.
Smile, Katarzyna, it's a useful social lubricant.
"Hello! I'm a magical girl and I'm looking for the paperwork to join a hospital volunteer program?"
"My name is Katarzyna Kozlov and I'm looking for the paperwork to join a magical girl volunteer program."