Invisible or visible disability? Is it even a disability at all?

Invisible or visible disability? Is it even a disability at all? Was having a conversation with my mum about this. I was saying that stuttering can be an invisible disability because the person might hide it, and she said that it's not really a disability - you can speak, you just don't like how the stutter sounds. She sort of meant you've brought this on yourself (not the stutter, the hiding it and turning it into a Thing) I don't know how I feel about this? Is she right? For context I hide my stutter very well around people and none of my friends know about it.