。
She got soaked to the skin.
Literal
She [topic-は] soaking-wet became.
ずぶ濡れ ('soaking wet, drenched') uses the prefix ずぶ as an intensifier — turning ぬれ ('wet') into 'utterly wet'. The same intensifying ずぶ shows up in ずぶの素人 ('a complete amateur') and a few other set phrases. The whole word is generally classified as a 擬態語 capturing the soaked state. ~になる ('become') turns it into a change-of-state predicate. Other 'soaked' mimetics include びしょびしょ and びっしょり — Japanese has unusual richness in expressing degrees of wetness.