How do you deal with LO saying mean things?

honeybee111

DD(3) has been in preschool since beginning of Jan. this year.  She goes to Montessori, and is in the primary class, so she is one of the younger kids.  The class is for 3-6 year olds.  Lately, she's been saying mean things to DH and I when we're doing something she doesn't like.  Her favorite phrases are, "I'm going to tell on you." and "I'm not talking to you."  Both said with total attitude.  She told me that some kids in her class told her these phrases.  So far, we've been telling her those are not nice things to say to people.  DH thinks we need to follow that with an action - like, if you want to say those things, you have to go to your room and say them by yourself, not in front of mommy and daddy.  Or put her in time out or something.  We haven't had to use time out in over half a year, so maybe we need to go back to it?  Or try something new since she's older now?