@Molass Hello! I heard from @Dazai_Dokja_wifey you were all looking for me. I regret to inform you that I haven't started this manhwa yet & sitting in my TBR since it was released, so I haven't commented anything yet 👀 but I remember reading a spoiler months ago, so my memory is hazy
Spoiler!
When MC woke up, she saw that she was wearing a necklace and female lead thought that this necklace belongs to her real family. Because of that, she always kept the necklace with her. The reason Diana sees her real appearance is beccause edre is Saintess reincarnation. So Mc figured on her own that Duchess is her mother. And mc told to the Duchess that she is her daughter, but when she said that duchess got really angry and say bad things.
Then Diana came and tell everyone that mc has beautiful pink hair and pink eyes, and she started crying. After that, they went to the temple and ask for a bishop, and when the bishop came, he used his divine power and reveals mc’s real look for a moment. it was really short, because the power in the necklace, which is too powerful, was more stronger.
I like to post spoilers for the stories I find interesting because I don't have much time to read novel due to busy schedule
you will find me in most romantic historical manhwa comment sections 
you will find me in most romantic historical manhwa comment sections 