If she is teaching business relations I'd say Speak English is the most important thing she can teach her students.

U.S. Americans will not deal with French Canadians unless the French Canadian speaks English to them. U.S. salespeople will not speak French when trying to sell to French Canadians though. The French person has to make the effort to understand. Some French buyers find it insulting because they think "he wants to sell to me. Why doesn't he make at least an effort to communicate in my language."

Our company has a booming brokerage business because of this. Some buyers do not know a word of English so we are needed to be the French arm of many businesses. I LOVE being bilingual. The opposite is not true though. The French Canadian companies that want to sell to the U.S. or rest of Canada learn to speak English. It is a bit of an odd situation.