I watched her though those junior high years and into senior

意思应该是:我看着她读完中学再升入高中.
“though”应该是“through”吧,如果是though的话那要怎么翻译啊?“though”的意思是尽管、虽然、然而,而根据你这个句子的前后关系,这里不应该有尽管、虽然、然而的意思,那就应该是through.