My sister-in-law teaches middle school in a district where there are white, African American, Spanish-speaking and a growing population of immigrant Eastern European families. Some kids don't have a working grasp of English, but in middle school they don't receive transitional teaching in their primary language. Some kids have troubled home situations. Some kids haven't eaten anything before school; lunch will be their first meal of the day. There are a good number of kids who come to school not ready to work, for any number of reasons. I don't think the teacher should be penalized, but it's worth a look at what keeps kids from doing well and get them into breakfast programs, family counseling, language support or other areas they need so they can do well in school.
Bookmarks