我妹妹成为一个大学生已经3年的翻译：My sister became a college student for 3 years 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

My sister has a 3-year college students

My sister became a college student for 3 years

My younger sister became a university student already 3 years

My sister became a college student has 3 years

My sister became a college student for 3 years