。
She asked him for help.
Literal
She [topic-は] him [to-に] help [object-を] sought.
求める ('seek, ask for, demand') with 助け ('help') as the sought thing. Recipient of the request takes に. Compare with ~に頼む ('ask, request,' typically less urgent) and ~に依頼する ('formally request'). 求める is more demanding — implies you actively want or need it, sometimes with urgency.