I'm still quite new at this luvhurts, but my initial feeling about addressing the kids is no. She is not going to feel the guilt that you would anticipate under normal circumstances. I think it may not be necessary to mention the kids at this time.
I understand how it affects us, and the desire to bring it up to them. My H is almost over-attentive to the kids. It is freaking them out a bit. He is going over the top to give them extra attention and get involved in ways that he never did before. I can see the look of confusion on their faces at times, and S15 tends to push him away if he is doing too much.