Answer:
I would say that "The main problem is that Hansel and Gretal's Father was tricked into thinking that his children would actually come back to him.
Oh and I would also change it by changing the fact that you wrote that "... it was actually the kids fault for running away.
And actually, The Mother did abandon her kids. When she tricked Hansel and Gretal's Father and abandoned the 2 kids.
Hope you like it! ;-)