No, Yumi-chan put it in a thermos and brought it to the club room for me.
Literal
No, Yumi-[suffix-ちゃん] [subj-が] thermos [to-に] put [and-て], club-room [to-に] brought [benefactive-てくれたの].
魔法瓶 'thermos' literally 'magic bottle.' 部室 'club room' (部 'club' + 室 'room') is standard school vocabulary. ~てくれたの combines the benefactive ~てくれる with the feminine explanatory の. ううん is the casual negative 'no / nuh-uh.'