。
She depends on her husband for everything.
Literal
She [topic-は] everything [in-において] husband [on-に] is-relying.
~において is a written/formal alternative to で when marking a domain, location, or time of an action. すべてにおいて ('in everything / for everything') is the stock phrase for 'across the board, in every respect'. ~に頼る ('rely on') takes に for the person or thing relied upon. Among words for one's own husband, 夫 is the standard neutral term; 主人 is more polite-old-fashioned ('master of the house', now somewhat dated for its patriarchal flavor); 旦那 is colloquial; ご主人 is the polite reference to someone else's husband. The sentence carries a slightly judgmental tone implying excessive dependence.