Well it isn't just the young riders who disregard safety. My former next door neighbor was 50 and always wanted to go on a trail ride with me. One I am not much into trail rides but the biggest reason is that she just didn't 'get it'. She was wealthy and her horses were really just accessories. She like many other people expected them to act like well behaved big dogs. They aren't big dogs. They are horses and for lack of a better word they have their own horse culture. What I mean here is that if you are a horse you have different rules to live by than if you are a dog or a cat or any other animal. Her mare would go into heat and kick other horses on the trail. When I suggested that maybe the horse was in heat when she did this she had never considered the idea. If I was riding that mare I would have ridden at the back of the line and if we stopped to talk I would put my mare and myself a bigger distance away. Anyway the whole horse thing for her pretty much ended in tears because she could not relate to her animals as horses.
I also always ride with a helmet. I watched my father die a slow death from a head injury and it really makes sense. Accidents happen in seconds and even the smartest most experienced rider can be injured.
As for jumping and riding in general it isn't just age that makes a difference. If you ride a lot on a lot of different horses you gain things that you cannot if you don't ride as much. I would like to ask if you have ever taken any lessons on a lunge line. It really develops your balance in a way you can never achieve otherwise. Some time spent with no reins is very valuable and some time without stirrups (less for an older rider) without having to worry about control changes your security in the saddle strongly for the better.
Once you really start jumping almost any horse more than about 14hands should be able to jump 3'. Once you get your confidence up a 2' jump is the same as a 3' jump. If you consider the jump just another canter stride just a slightly larger stride it changes things quite a bit.
I somehow ended up with the right crowd with horses at a young age and was in a position to take advantage of some wonderful opportunities that came my way.
If you do throw in the towel on the horse ownership and jumping part remember that there are many ways to experience horses. There are plenty of places who could really do with a safety concious mature woman to lend a hand here and there. You are an asset. I have found myself at times drifting into different roles, caring for rescued horses at the humane society, rescueing horses myself, volunteering as a ring steward at horse shows and jump judging at hunter trials. I have held volunteer positions in horse societies and tacked up horses at riding establishments in exchange for riding privledges. I have sat and comforted little girls in ridng boots who felt they were not going to do well enough at horse shows and lent a hand as a groom for people who needed a hand.
Somehow though I know that you are going to be okay. You will always be a horsewoman and no one can take that away from you. Have fun and accept yourself and your horse for what you are and tell anyone who thinks you should do otherwise to stuff it!