How can I teach girl the lesson that what she did was not right?

Sometimes and I know this may be hard to do especially since you work together but ignore her. Straight up. Get you a new person to gossip with and everytime you and her get together make it seem like you are having the best time ever. She will take notice. But don't be rude to her just ignore her. She'll wonder why you are not mad or being bi**hie back and like they always say kill her with kindness but dont go outta your way or nothin. Be suttle about it. Don't look at her when you walk past. Sounds childish but trust it will work. Get another co-worker to hang with and make up something silly that only the 2 of you know and laugh loud when your around her but never make wye contact. Believe me a combination of all the above will eat at her inside and I bet she'll come to you like why don't we talk/hang out any more. Then the in your court!!! Hope that helped....