问个英语翻译句子的困惑

She had bought the tickets before i went there.
因为”我赶到”用的是过去式，而买票又发生在”赶到”之前，所以用过去完成式．

Before my arrival, she had already bought the tickets.

我赶到之前，是一个具体的过去时间。
在一个具体过去时间已经完成的动作，不用过去完成时，你想用什么呢？

因为在你赶到的时候,就发生在过去,用过去时,在那之前发生的事当然用过去完成时了.

She had bought the ticket before I got there.