It took DS 4 years to learn the word 'stupid' but thanks to school he soon added that wee gem into his vocab and now DD 22mths is parroting him, over the last few weeks it's gotten really bad, she is saying stupid / stupid head with alarming regularity and in perfect context! We tried ignoring it for a while but she carried on and it got worse so we started saying 'that's not a nice word, we don't say that word' of course made no difference as she's still practically a baby... today I tried redirecting her to say 'silly billy' which she quite liked.
Honestly it sounds terrible on such a little person but the sanctions we put in place for DS just won't work for her, any advice on how to deal with this?