The ice is necessary keep the provisions cold and make sure they would be edible for a longer period.

[She explains, it seems unnecessary but she does it in benefit of whoever listens. She addresses what she believes Rinoa asks next.]

It would either be individual supplies for households or just one this potential storeroom. I have another volunteer, so the task would not be a burden for a single person. [Two more, but she will keep Rin's participation secret.]