。
She still hasn't cleaned her room.
Literal
[topic-は] still room [object-を] has-not-cleaned.
掃除する ('clean, do cleaning') is the verbal use of 掃除 ('cleaning, sweeping'). 掃除していません is the polite negative resulting state — 'is not in the state of having cleaned [it].' まだ paired with this gives 'still has not cleaned.' Cultural backdrop: 掃除 occupies a particular place in Japanese life — public school students clean their own classrooms daily (a practice rooted in Buddhist training and meant to instill responsibility), and home cleaning is often a moral as much as a practical activity. So 'hasn't cleaned her room' carries a small ethical sting beyond the strictly practical.