dyou still have the copies of those articles? post it into your blog then so she cant. as those articles in her hands will be subjected to plagarism
There is nothing you can do about this situation unless as stated by someone else in another post, you have a written agreement, then you can take action. I suggest you try and sell your articles.
oh my god...very sad to hear this, you must hav spent all day, all month..writing those articles,..the experts in dis threads hav given u , enuf suggestions,.. follow thm ..you r good to move ahead thn..be carefull in the future..,
Take screenshots of those urls along with Google Cache (google it Cache:www.sitewhereyourarticlesareposted.com) as well, in case they delete those articles or vanish those urls. That will be an additional proof to have in case your situation goes bizarre.