1. Yuuu... Chake me up big shis 2. Big shis... Happinessh~ ....... 3. Why... 4. Why are you ignowing mee!! Chake me uup!! 5. Yuguuuu!!! But Maricha... Can climb... 6. Yu"nn! 7. Yungu'.... 8. Yu'~!?
My guess is she probably didn't know, and this is the first time this happened. (She probably didn't move around a lot before.) If it's not permanent, she has two choices: either keep it on and remain a cripple for the rest of her life, or throw it away and be branded a non-easy-taking yukkuri.
all of the choices it had doesn't matter, it will be killed shortly by it's sister of course not before the big sis convey all it's hate to it first which 100% will be answered by "why did you choo that" shit or something
I would say "Bottom line: She dies, big sis dies by mum's wrath. These stuffs gets predictable in the long run" but i would hold back for now, my plot-whore mindset tells me there's a plot twist to this >~>
There's one more choice you're all missing. She could remove the shell. Since she was weighted down by it her whole life, her muscles had compensated, so without the shell she'll be super-strong for koyukkuri standards. With her pent-up rage, and element of surprise, she easily defeats her sisters, and steals her hat. Then, she hides the hat under the shell, and when parents return makes up some story about her sister having an accident. The parents buy it, because there's no way the little one with a heavy shell could do anything to her. Shell Marisa begins plotting world domination.
@Easy Modo: I thought about that, but I actually doubt it; she didn't move around a lot, and when she did, she did so very slowly, like a normal koyukkuri carrying a heavy load. So I think she'll either be normal or weaker, more likely weaker than the average yukkuri due to atrophy of certain bean paste parts she hardly ever had to use, since its mother was next to it its whole life - she even took her out for pee-pee, if I recall correctly.