A young girl is reincarnated and remembers that she is born to be a sacrifice for her brother. Her father then later asks about it and she decides to lie and say that he is too competent to let that happen (in order to gain his favor so she won’t die).
I lost it and I really want to read it again, can someone please tell me the name?
A Queen's Law of Survival seems to match your description.
From Baka-Updates:
She used to be an immortal. She gave up her immortality for eternal love, yet was betrayed by the one she loved. In a twist of fate, she was reborn as a queen in another world. Now, she is faced with the ever-impending danger of being sacrificed by her cold-blooded father to her brother. Can she find a way to rewrite her destiny...?
A female cultivator is reborn in another world as a princess named Alisha. Even as a baby, she retains her adult intellect and memories from her previous life, and learns that she's to be sacrificed when she's older to save her twin brother, Arthur, from a curse which is due to kill him by the time he's sixteen.
She's initially raised by servants in a separate palace from her father and brother, and when she finally gets to meet her father as a little girl, she attempts to win him over with flattery, insisting that he's powerful enough to protect both his children, and ensure that they can all live happily together.
