I went to see her only to find her out???

我肯定的是：“out”是“宾补”（因为书上是这么写的）

请问： 主语——I、谓语——是“went to”+“see”吗？、宾语——her
宾补——out
那么：only to find her——在句中做什么成分？？

Mary must have gone to the cinema when I went to see her yesterday,__? on her trip to see her parents是什么句子成分？ I went closer to them to see that ... ---HIS birthday ,I went to the party----her invitation I went to BeiJing I see her here,I see her there I rode brooms and started round-the-world. I need to see where I went to help. I went to her dorm,our dating place.What configuration is in that sentence? i had gone to see her yesterday,but i haven't gone. "I see her ____the clothes every day on my way home."