。
In the evenings I help my mother.
Literal
Evening [topic-は] mother-of help [object-を] do-[habitual-ている]-[polite-います].
An example of ~ている used habitually. 夕方は fronts the time as a topic, and 手伝いをする uses the noun 手伝い ('help, assistance') as the object of する. Compare the verbal alternative 手伝う ('to help') — both routes give similar meaning, but using the noun form feels slightly more formal or structured.