Hm. Sounds like something to bring up to a doctor actually. If she’s comfortable and willing. She could have a birth defect or could have had surgery in the area that could have damaged nerves, or she was injured and damaged nerves.
The clitoris is larger than what you see and it might be able to be stimulated from elsewhere if it isn’t injured.
In the meantime try for the g spot and vibrators everywhere until you maybe find something that works.
But yeah, worth mentioning to a doctor.
I go to a monthly meeting for a society I’m in and it’s like this. We eat, drink, and watch a presentation. It’s cool, I like them.