。
She didn't want to talk to anyone.
Literal
She [topic-は] anyone [to-にも] talk-to [didn't want to-たくなかった].
誰にも + a negative predicate yields the universal 'to no one / not to anyone' — built on the broader pattern of 誰も/何も/どこも + ない for blanket negation. The に in 誰にも is the dative target ('to whom'). 話しかける ('to address, to start a conversation with') is a compound verb (話す + かける) that specifically names the act of initiating speech directed at someone, distinct from plain 話す ('talk'). The desiderative ~たい inflects like an i-adjective: 話しかけたい → 話しかけたくない → past 話しかけたくなかった. Layered together: a textbook portrait of someone in a withdrawn, antisocial mood.