Co-worker drama, how would you deal with it?

How would you deal with this? You have a co-worker who is really nice and is a great friend, but has a lot of drama that is brought to the workplace? The boss doesn’t care for her, but likes you and you’re worried you’ll be passed up for a promotion through association?

This isn’t my current situation, btw, just a past situation that I was unsure how to deal with.