Until you know for sure what is going on be very careful with the kids just because you never know.
I would concider calling them and asking them questions like did anyone mess with her while she was eating ect... NOt saying they would be honest but it might give you a clue.
Here is just a thought is it possible for her to have gotten food aggressive just because of the stress being away from home with other dogs around. Their instint tells them to protect their food.
