Welcome to pprune and I hope you're enjoying your flying.
Depends what you mean by 'share'. I usually write my notes in front of the student following the de-brief or if there isn't time then, read them out at the beginning of the brief for the subsequent flight. There shouldn't be anything in the notes that yore not prepared to discuss with the student.
If you mean 'let you take the notes away with you', then no, that never happens. If you change school, then the notes will be sent direct to the school, never given to you to take. If a school closes down, then the notes should all go back to the CAA.
I've had students which I've shared with another school, as they spent part of their time in different locations. Under these circumstances, I've contacted the other school and we've shared notes by e-mail, which when printed, have gone in the student record.
TOO