Short workplace exchange. あがる ('to go up, rise') in this work context specifically means 'to finish one's shift, clock out' — the potential form あがれる then means 'be able to finish/leave'. 終わりまで ('until the end') refers to the end of the whole shift/event. The sentence-final わ is the soft feminine assertion particle. 要 (かなめ) is a name; ~さんっては with rising intonation is the colloquial topic marker 'as for ~'.