This made me chuckle because my RB Puddy was a hisser, so much so that when she became ill w/CRF, I told my vet that I wanted her hiss back. She was a beautiful 5 lb. calico that looked harmless but that look was deceiving. A couple came by once and brought their little girl and I forewarned everyone that all my cats could be petted except her. Of course, the little girl didn't listen and Puddy wrapped herself around the little girl's ankle and dug in w/teeth and claws. As long as everyone left Puddy alone, she left them alone but if you came too close, she'd hiss. That's their warning mechanism telling you to back off. As Puddy grew older, she didn't hiss as much, especially when she became ill. I guess it just took too much effort so when I did hear a hiss, I knew she meant it. It may just be part of your cat's personality and she may let up on it a little as she ages but don't count on it. LOL Good luck.

Btw, welcome to Pet Talk!