Dealing with TEENAGER and clarification on the model

C – daughter showers 40 minutes – 60 minutes daily
T -Waste of water, not good for her skin, not good for the environment, higher water bill
F – extremely annoyed
A – can’t focus on anything else while she is showering
R – suffer in silence when she showers

So I understand the concept that the C line is not supposed to cause my feelings, but not clear on how this really works since I just want the C line to change. I would feel so much better if she showers for 10 -15 minutes instead!

Should I change my thought to it’s ok that she is showering fo 40-60 minutes? That’s not wanted though.

Isn’t it different when dealing with a teenager and not another adult and I need to figure out a way to curtail her shower time?