Help me find this manhwa

It's shoujo
The fl has white hair
She's some shorts of image of a white lily (?)
She has some illness that she can only live for a shirt time, she had bad relationship with her family but it get fixed up during the time she isolated herself.
She made friend with dark hair knight ( Or duke something idk) cus she said she had never had a friend.
I swear i don't remember the title at all.