She's got a history of herself going on, late on Sunday night on Radio 3, but as far as I'm aware, she has not let on what prompted her to put the professional violin bow down.
O Wikipedia, it just mentions giving things up recently, but no actual reason for it. I wonder if she has early signs of Parkinson's disease, or a similar difficult predicament to get her thoughts round.
Does anyone know more fully what prompted the retirement?