In August, I started doing contract work for one of my former employers. I have a great relationship with my former colleagues, and it's been great.
Another person contracting for a different part of the company is my former boss from another company. (That might be tough to follow - I worked for FormerBoss at Company A then later went on to be an employee of Company B. Years later, FB started contracting at Company B, then I started contracting at Company B in August.)
Anyway, my time at Company A didn't go so well and certainly didn't end well. This was in part because I was young and stupid (12-13 years ago) and in part because FB is BSC. I haven't spoken to this woman since maybe September of 2000.
Now we are on a small project together at Company B. So far, all contact has been over email. I dont' think she realizes who she is emailing with, because I have my married name now. I don't have any issues working with her - I am more grown up now, and her role is small - but I am wondering whether/how to out myself as her former, disliked, employee.