Go to a health food store and they also have some good ointments.

made from rooster combs that eases pain and acts as a cushion on the knee. My first one lasted 7 years. Second one was two years ago. Looks like I'm ready for another soon. But it totally relieves pain, not immediately, but after a few weeks. Think its called hyaluronic acid. Medicare approved.

Have received this treatment in both knees and it is absolutely wonderful. Highly recommend it.

Contains cbd hemp. Cooling. It’s not available in every state but it works wonders.
Voltaren gel is also good and available everywhere.

I've found if I limit my walking and sit with my feet elevated every time I sit down I'm able to keep the pain at bay. My situation probably isn't as severe as your mom's, but the story is familiar. I've had the cock's comb injections, which may have helped a little, but they're no long-term solution, and the brace my orthopedist put me in is uncomfortable so I generally don't wear it. If it helped, I'd put up with the discomfort, but I can't tell any difference whether I'm wearing it or not. I've decided to get a really good Rollerator walker--the kind you can sit on if you need to--and see if that will take care of my walking problem.

I couldn’t get around without them. I’m 71 with weak knees and a bad lower back. Not a good combination.

one or the other will start acting up by collapsing or pinching. The pinching hurt badly when I put weight on the knee. It started pinching a few weeks ago and I found one of my old sports braces and put it on for a couple of days. Soon the pinching ceased so I guess it was giving support in the right places to stop the pinching. Maybe that could help your mother if she is willing to try wearing it for a little while. I took mine off after the pinching stopped and haven’t had it back on since, no problem. Good luck.