A three year old with a Nuk?

Yes I know. My three year old is still attached to this pacifier in her mouth. I took it a way from her one time and it worked for a couple of months but then I had a new baby and with a new baby come along new nuk's. She had pretty pink one and I purposely got his to be blue and boys, but now she steels them from him. Last night I put her in her bed and she begged for the pacifier, I told her three year old are too old bla bla bla, (we don't allow it) but She got up about an hour later, I heard her go into her brothers room. When I snuck in there to see what she was doing she had crawled into his crib and taken his right out of his mouth! Of course this didn't fly with me, but what can I do to get her away from wanted a Nuk?