Okay, so some mysterious player (the templars) have whisked away her children. Since she's 39, I suppose she conceived late in life, they'll probably be teenagers by now. The boarding school idea still works. However, this must have happened only recently, since the father remains clueless. Perhaps she has forged letters from them in order to keep up the facade.
That would give her yet another reason to work for the information broker, heck. Maybe he has promised her information on her kidnappers if she work for him.
She is willing to do anything concearning her children, even walk over bodies. No doubt a little added power would also help her find her children, so that makes sense for her to pursue. It would also explain her travels since she's not sure where her children are being held, and possible missions from her employer. Perhaps since she is yearning for adventure, she has even come to enjoy herself despite being consumed by worry. No doubt that would create shame.
But besides finding out about her kidnappers. What is she planning? She doesn't know her enemy yet.
I should probably mention, that the templars are protecting an ancient secret from leaking out. And some of the noble houses in her country are unwittingly tied to this secret. In fact, in one way, the whole country is. While her house secretly aided one specific house that was destroyed due in part to the meddlings of the templars. Her only tie to that house is her friendship to the last remaining heir, who has been made an outcast. But I don't think the templars find him important enough.
Also, as a further twist. Her husband has had an affair in the past with another noblewoman. A powerful widow who can really be described as the spider in the web when it comes to local politics.