Their plan seems ridiculous now it's failed, but in the other timeline it would have worked.
The maid swayed by the fortune of coins would have done it, and if she still had been that frightened, timid child, the head maid would have stayed silent and ignored what happened without examining it. But because the young girl stayed calm and gave them impression that she thought the head maid was in on it ( and might say something), she stepped forward and confessed it. Dumping the maid and the guests in it upto their necks, whilst saving herself by distracting the dukes attention away from her. She doesn't have I'll will towards the kid, but she values her own life more.
The maid swayed by the fortune of coins would have done it, and if she still had been that frightened, timid child, the head maid would have stayed silent and ignored what happened without examining it. But because the young girl stayed calm and gave them impression that she thought the head maid was in on it ( and might say something), she stepped forward and confessed it. Dumping the maid and the guests in it upto their necks, whilst saving herself by distracting the dukes attention away from her. She doesn't have I'll will towards the kid, but she values her own life more.