Katylin is a plump dragonite who is equally large in all three B's. Personality-wise, she's not all that shy like most other chubby pokegirls, though she's never too invasive of personal spaces either (though she does give pretty good hugs)

While she's open to all methods of inflation, she transfers however many feet she gained during the growth and spreads it out equally to all other girls present when she wants to return to normal, with the favorite B's of each girl getting the brunt of the growth along with their secondary favorite of the B's

Feel free to introduce yourself or another pokegirl of yours to her, just keep in mind of that one trick she has when inflating her.