Responses
I don't think the mother tried to cause trouble in the end. She was just telling Sensei the truth that they were going to start over. It's just that Sensei was not able to listen to the end and thus assumed that they were going to start over as a family when actually, they were really starting over from further back when they were before a family.
The mother is a real loose-goose (as nice as I can put it) seems she couldn't help but try to cause trouble even till the end. I wonder what the precocious Taiga thinks of his mother?