。
She works as hard as anyone.
Literal
She [topic-は] anyone [to-に][also-も] not-being-inferior well works.
誰にも劣らず is a fixed comparison frame, literally 'inferior to no one' — i.e. 'as good as anyone, second to none.' 劣る ('be inferior') takes the standard of comparison with に. The ~ず is the classical/literary negative, giving it an adverbial ('without being inferior') sense — essentially 誰にも劣らないで in modern grammar. The whole phrase 誰にも劣らず is a productive frame: 誰にも負けず ('losing to no one'), 誰にも勝てず ('unable to beat anyone').