Hi Caroline, I enjoyed reading your post as it pulled the rug out from under some assumptions I was standing on while reading it.
I just assumed you were a guy. I was getting ready to tell you how I had super duper long hair and similar experiences, then how cutting it was no big deal. Then you signed your name
Outside of a Buddhist context I think some women look fantastic with short hair. Some women, but not all. It is a bit like a man getting a crew cut. It works for those with the shape of head and facial structure for it. In my opinion, women, even with grey hair look better with it long. Most women look neutered with short hair.
In a Buddhist context the only way I can see hair length mattering is convenience and then only for monks or very dedicated meditators. A shaved head cuts down on grooming time and the number of possessions you need to own.
I don't think hair length makes much of a difference for a lay person. I had hair down to my shoulder blades for over 5 years at least. I've had a typical short man's hair cut since then. I don't get that much more practical utility out of short hair. Pulling my hair back into a pony tail or a bun worked out just find. I do spend less time on grooming it. I haven't turned my hair dryer on in years. However, I find it to be nuisance to have to go to the barber at least once a month. With short hair, it grows out enough to look messy fast. Haircuts, at least good once aren't cheap anymore, so that is the other down side with short hair.