I don't think submissive and emotional self-mutilation fits in the category of regal beauty. You were the one pointing out what Sarada was showing.
I am just going along with the thread, so if Sarada is showing something it is due to her Haruno genes, which should be that DNA part that makes her behave like a common leaf tramp. We know that Uchiha's are the closest to royalty that Sarada has in her DNA.
It has everything to do with Sakura. Sarada is her daughter, Haruno genes have nothing good to them. What Sakura achieved was through hard work.