Thanks for your replies I appreciate it. The whole thing kinda freaked me out yesterday as I'd never been put in that position before.
Just to update you on the situation in case you're interested; in the end I replied to her message publicly on my blog and also sent an email to her expressing my concern and trying to be as positive as possible. I suggested if things were really that bad that she should please at least call the Samaritans and gave the phone number & email address. I also phoned the Samaritans myself to find out if there was anything else I could/should do. They really are amazing people.

To my huge relief I received a response back from her this morning and thank goodness she did call the Samaritans and is in a much more stable frame of mind now. She apologised for scaring me.

Thanks again all of you for replying to this, and Caramel, no, my online name is RescueMyLife (or Anonymous Drowning Man) - when I reply to comments on my blog I sign off: RML - this particular lady decided that 'RML' sounded a bit like 'Caramel' and she's been calling me that ever since. Don't worry - you're still unique

All the best - panic over & thanks again.
RML