Personaly, I would not play the game. Reverse or not reverse. I will ignore it and wont discuss it at all. If it happened again - I will say that this is the second time now that she forgers what she has done and it makes me concerened that she might need to be checked up. I would not say more than that. But I guess that once you are aware of the situation (and you know your mum best) it is your call and decision.