。
Before that, she had never spoken to him at all.
Literal
She [topic-は] that-before him [to-に] addressed thing [subject-が] [completely-まったく] not-existed.
Several pieces of nuance pack into this. それ以前 ('before that') anchors the time frame to a moment already established in context. 話し掛ける ('to speak to, address') is a compound verb (話す + かける) for actively initiating speech. ~たことがある is the experience pattern ('have done X (at least once)'), and its negative ~たことがない means 'has never done X.' Add まったく ('not at all, completely') in front of the negative for emphasis — まったくなかった = 'absolutely none, not even once.' The result is a strong assertion of zero prior contact.