Also are you trying to piss off the girl with military training, and possibly carrying a butterfly knife? (Edit this wasn't meant to be mean or threatening it was just me laughing a bit.)
Anyways there is a very easy way to disarm her that should be fairly obvious/hard to ignore way to disarm her.
As Lucille returned from getting some shower supplies she looked at her summon and sighed as she skipped in front of her. She'd look over thinking about what she expected of her summon and the reality of what she got. What was she going to tell her mother about what her summon was like. At least her grandmother may accept or would she, her summon was quite counterproductive to the idea of medicine after all.
"You are a bit strange for a summon aint you." She'd say not trying to offend but still curious what was actually wrong with the thing.
"By strange you mean strangely awesome."
"No I mean strange" she'd say frustrated.
"How am I strange? " she'd say earnestly wondering what she was talking about.
"You are some sort of plant thing, I can't even tell what kind of plane you come from unlike the other summons. You're probably so fragile I bet you would fold over and die in one second in the arena. You somehow smell great and awful at the same time, and best of all you don't shut up." about to spew fire at her if she didn't understand.
"I will shut up." Isabella would say as she sat there her flowers would turn blue and point down to the ground. Trying to look away from Lucille as to not bother her. Lucille would at first be uncaring happy to finally have the silence she was accustomed to as the crowd seemed to part currently for the two of them. Lucille would think about the incident and realize it was probably what was parting the crowd. "Was it a actual attempt to help." She'd think to herself as she looked at the seemingly dim witted plant.
"You know I'm not the most normal summoner I guess. So maybe you're a great summon for me. Perhaps you could talk" She'd say trying to cheer her up.
" Like your hair of orangaye?" She'd say looking up as her flowers returned to normal.
"Yup."
"Like your bad skills of social, poor self confidence, and age of being a "brat"?"
"You can stop now."
Meanwhile the two of them would finally arrive at the dorm a bit later. She was just tired and ready to clean the stench from her summon off, coming in as the two exited the portal. She'd look around seeing whose cloths were everywhere a bit annoyed at who the pig sty was. Though she slowly noticed that they were her own and hr face would turn red out of anger and embarrassment again standing there unable to think, yet to scared to speak. Meanwhile her summon would be busy being herself as she stood there, "Are these yours? Your cloths, and petals come in so many color. Look these ones have pokey dots, and these one have a tiger of light." she'd say holding up a pair of hello kitty underwear finally angering Lucille enough to explode. "Which on of you did it?!"