@Rosi2 and@phatman
About the personal bathroom, it was not her invention. Such bathroom is not only a normal thing that existed in Ayutthaya time, but also in our generation. In BPS you had seen the bathroom, it was down there outside the house. People would not build them near their houses. At night or when it rained, it was inconvenient to go down outside the house and it was unsafe from poisonous animals like snake, scorpion etc., so they had to have a bowl for this on the house.
In Ep.1 Date and Karakade talked about the personal restroom as well when Date asked Karakade if her maids set up a bowl for her or not, why she had to go to the bathroom outside the house at night. She said she went to number 2. It would stink if she did it on the house. Pin and Yam would smell it all night, so she went down there.
When I was young, our restroom was outside the house including the bathroom but the bathroom was near the house. We also had a personal one on our house too.