My dd is 14 and goes to a performing arts high school. She gets striaght A's and follows the rules. She hasn't asked me to date and loves to go out with friends. I have let her get her ears pierced and she now has three holes. SHe asked me to get the underside of her hair (which is long and curly) dyed red. So, I let her. My MIL flipped out. She said between the ear peircings and now getting her hair dyed she is going to look like a "hood". Another mom said she would never let he dd dye her hair until she was 18.
My opinion is she is a good kid and wants to have some fun with her appearance. This is the time to do it.
Let her express herself while teaching her limits and responsibility. Everything in moderation. Let her live a bit now cause once she is older she won't be able to do all that anymore. She will be in school and or working and will need to be a responsible adult. I hope what I said makes sense.
I think what your daughter did is just fine. My daughter did the same thing and is an honors student. Transforming your body does not suddenly make you "dumb"! My parents also didnt like what my daughter started wearing....saying she was turning "goth"....but ive seen "goth" and she was not doing that....she was wearing a couple of black shirts or black pants (not all the time) and that suddenly made her "goth". Old fashioned parents is what your MIL is! My parents are also 'old fashioned'. NOW if your daughter started flunking all her classes than maybe she did get too many holes in her head! Just kidding! LOL! :)