D.B.
It's important to substitute another word for her. My daughter used "Ratsticks!" I don't know who told it to her, but it was a fun word to say with lots of consonants - some kids like that. Another friend used "Bummer!"
As for other people's comments that the kids say, "Well, Daddy uses that word" or similar responses, I have a good friend who told her 8 year old, "I know. I shouldn't say those words and neither should Daddy. However, Daddy has driving words, and Mommy has cooking words, and whenever you can do either of those activities on a regular basis, you can use those words!" That was a great response, I thought! LOL!