Well I'm sorry ... I've interviewed a lot of people firstly for my thesis ... criminals ... and what I disclosed to them was extremely controlled and only in response to WHAT THEY ASKED ME.

I've been taught to interview by real professionals (thank god) and in my current job, if I introduced bias while interviewing something (which is what you did) I'd be unable to use that interview as valid data

If she'd asked you about your kids ... yes, you could have introduced what you did.

But as an interviewer your job is NOT to 'bring in your experience as a birthmon'. If you are going to challenge your subject - which is perfectly acceptable - you may call on your own experiences, but you'd ask in a different way - e.g. neutrally - if that was appropriate.

i'm sorry but protocol dictates that you're careful about who and how you disclose personal information to. It doesn't break the ice. You may normalise something in terms of says 'Some people I've spoken to think .... do you agree / disagree' ... but unless it's asked of you you keep your own history out of it.

Otherwise you're introducing bias.

Good luck