姐姐在卧室读书英文怎么说

你可以说 "姐姐在卧室里看英文书" 或者 "姐姐在卧室里学英语"。

这两个短语的来源都是来自英文。"看英文书" 是 "read an Engpsh book" 的直译，"学英语" 是 "study Engpsh" 的直译。

一些英文例句和中文翻译如下：

My sister is reading an Engpsh book in her bedroom. (我的姐姐在卧室里看英文书。)
My sister is studying Engpsh in her bedroom. (我的姐姐在卧室里学英语。)
She is reading a novel in Engpsh in her bedroom. (她在卧室里看英文小说。)
She is practicing her Engpsh skills in her bedroom. (她在卧室里练习英语能力。)