Kyoko's main hobby, as a manager, is to... sweep leaves and dust in front of the house... It sounds like a common hobby, but she admits herself that it relaxes her and it allows her to think...
But it's not only that... throughout the story, we will notice she's able to express a lot of things only by letting fly a few leaves, by sweeping when there's nothing to sweep and resting, thoughtful, hands on her broom... moreover, that central position, in the house's entrance, allows her to watch the comings and goings of all of her tenants...
After all, her work is to be a caretaker... she needs to be informed about what's going on... ^_^
Kyoko, while working, often wears an apron with a chirping birdy on it, as well as the words "Piyo Piyo" in romaji. Beside it's a common design at that time on several objects, that apron has a symbolic meaning concerning the character's psychology.
Actually, this is the onomatopoeia for a little chick peep. It's there to hint at the character's youth, immaturity and refusal to move on in life. At the end of the story (in the movie, "Maison Ikkoku, Final chapter" and neither in the manga nor in the TV series), Ichinose gives to Kyoko a hand-embroidered apron with the words "Koke Koke" (the onomatopoeia of an adult hen clucking) and a big hen on it... meaning she moved on in her life and grew up.
As for her work, Kyoko, of course, doesn't only sweep all day long. There's repairing broken thing, getting mail, doing laundry, taking care of the garden, etc... she does her manager's job and Mr. Otonashi agrees with me that she's doing it quite well ! ^_^
The main quality of Kyoko, as a manager, is to have been able to make a family out of the loonies in the house and her main merit is to have been able to resist the ambient madness, the tenants tending to be (Godai is probably the more normal) obnoxious, lazy and sometimes gratuitously evil. She knew how to make them attached to her and by her patience, her kindness and her disarming ingenuity, gain their respect and, in a particular case, their love...