When is being a supportive friend become being too supportive?

I have this friend where we have been friends for over 7 years, we have always been there for each other. The problem is that I sometimes can be too supportive to the fact that I even put my values to the side to support her actions or behaviours, which I dont necessarily align with. It upsets me because I want to be a good friend but doesn't that also mean being honest with her? Also she doesnt take critism well, opinions well, so I didnt want to make her angry or upset. I feel like I'm being too supportive that its unhealthy for both of us.