D - I have to tell you something. My H always preferred my hair long and natural, too. Over time, I began to feel smothered by that insistence. I wanted to be an individual, try new things, and I felt like he was attempting to control me - hold me back from being who I wanted to be. It's funny that hair can become an issue - but it did in our M.
Once H found out I felt that way, he told me to do whatever I wanted. He wasn't trying to control me. So, gleefully, I went running out to do something different with my hair. When I came back, though, he was so underwhelmed and non-admiring of my new 'do, that it made me feel really badly...and still controlled.
I'm pointing this out to you, because it's possible your W felt very much the same way. I understand your reaction, too, because of how my H reacted. He just preferred it one way, and I preferred to experiment and try new things. It would have been so much better if he could have supported me. His silent disapproval felt so much like being controlled. I finally got to the point I would do what I wanted with it, without expecting much in return. He took that to mean I didn't care about what he thought.
Examine this feeling, D. He was controlling me - and it was just hair! I just wanted to try new things, and H took it as a personal affront. Has your W ever said she felt controlled by you? Like she had to do what you wanted all the time? It's possible you may have stumbled onto another area that needs to be examined in yourself - not for her.