Read The Real Daughter is Back Manga:
Helga Yttri, a half-noble lady who inherited the blood of a lowly maid. A bastard child who was swapped by the Duke’s maid; a Fake child. Helga gave her everything to be recognised as the real daughter.
"Your Grace! The real Young Miss is alive." "Her name is Hyllian...!" Helga prayed to God countless times so that the real Young Miss never returned. " ...don’t come back, Hyllian more.. ." "Don’t come back, please." She wondered if her prayers failed to reach God because she was a fake daughter. "Dear God, I’ve been praying countless times." "I asked you never to let ’that child’ return." The prayers she howled until her throat went hoarse was all in vain. "The real daughter of the House of Yttri, Hyllian... The child who will destroy my whole world." The real daughter is back.