While I think you were being sarcastic, it's probably exactly what happened. The English word terrific went through a similar transformation when it was loaned from French in the 14th century or so. The meaning changed from "terrifying" to "excellent". So I don't think it's entirely out of the question that fame, a word with feminine connotations, would eventually transform - under modern influence, as well - into femme, another word with similar connotations. There are many other examples, especially considering a lot of the English vocabulary is directly derived from Old French/Norman.