Well, I am old enough to be your mom and I can't believe your mom won't "let" you ride alone. You are an adult. Sit down with her and tell her all of the safety precautions you take. She should listen to you and understand. But, after that, if I were you, I would still go out alone. I mean, do you have to tell her everything you do? I bet you don't tell her other stuff...
My son started riding and racing at age 14. I worried when he was out training, but I knew he was doing all the safety stuff and he would call if he needed me.
Good luck.