id personally make a trip to see her face to face, tell her calmly that this is not on!
its more confrontational (sp?) face to face imo
i remember reading your thread last year, and im so sorry this isnt the end of it for you and that she keeps getting involved in your lives...
just one thought though...
you say you asked dh only last week if he had heard from her....do you think dh got paranoid that you know something and were asking him so that he could have a chance to come clean...
...thought about it, then volunteered the information that she got intouch...hope you see what i am trying to say, im not too good with words.
it seems of a coincedence that he hasnt heard from her in ages, then when you ask, bang, out of the blue she got in touch a week later
did he ever stop being intouch with her?
sorry to be so blunt and brutal, but its something i thought of and perhaps you should think of that possibility