。
She moved the clock hands forward by 10 minutes.
Literal
She [topic-は] clock [possessive-の] hands [object-を] 10-minutes made-advance.
進ませた is the causative of the intransitive 進む ('advance, go forward'). Japanese frequently has both options for moving something forward — the dedicated transitive 進める, and the causative-of-intransitive 進ませる — and they're semantically near-identical here. Some grammarians argue that with concrete objects (clock hands) the transitive 進める is more idiomatic, while the causative 進ませる feels slightly contrived. The 10分 here is a bare measure-noun adverbial — Japanese routinely positions duration/quantity expressions adverbially without a particle.