So, what if her sister was richer than her?
Wasn't the money still belonging to the family?
If she was stingy and never spoiled her, she might develop some crazy thoughts, but her sister's generosity knew no bounds. So those thoughts were squashed before they could even develop.
So, listening to her sister's earnest advice and how she didn't sound resentful for many things. After all, as sisters, they were different completely, and Ruby was glad to have such a sister on her side.
"I will keep that to memory, sister. Don't worry about this. I promise you!" Ruby promised her sister earnestly, knowing that if she didn't, Diamond wouldn't calm down.
Diamond heaved a sigh of relief surely upon hearing that.