New Bosses

I have a new boss as of the last few months. I’ve just discovered that she has been persistently undermining me and some of my colleagues. In the past these people have all worked seperately with few if any issues. She is now saying that she has always seen us as a team. In fact, she is now trying to appear to be bringing this team together. So having completely undermined and demoralised these people she is now being seen to build this team up. From the point of view of these people, we have only been a team for a couple of weeks. How do we deal with these issues without giving her the satisfaction of going around and telling everyone what she has ‘acheived’?