I agree that the balance bike is a good idea. They are pretty popular at bike shops. They say it is a better way to learn than training wheels.
M was 9 when she learned to ride. Nothing I did could teach her before that. (This was long before balance bikes) Like your daughter, she just got tired of watching her friends ride, and eventually took her bike out on her own. She came back with skinned knees and elbows, but knew how to ride. She just had to be ready, and it had to be her idea, and she had to do it her way.

I don’t know where you live but the university of Illinois at Champaign-Urbana has a learning to ride a bike program for special needs. There must be other programs out there like this. Talk with your therapist last for your child or the county for mental health or maybe Easter seals. PT therapy would be good too. Good luck

Physical and occupational therapy might be able to help

Don't fear, my 16 year old just mentioned she wants to learn how to ride a bike. We got adult sized trainning wheels for her bike. Got done with Henri's water and not hot and too humid to ride right now. It will be started before school starts. We have fog now too.

No idea. My 16 1/2 years granddaughter wants to learn. My husband will teach her. I'made just getting used to use my bike.