Oops, Daddy, She's My Mom!

DramaBox synopsis

After a one-night stand at a hotel, Eleanor got pregnant with Damien's child. During childbirth, the baby boy Lucian was swapped by the nurse Kelly on Livia's orders—Damien's socialite wife—and was falsely declared dead, leaving only the frail baby girl Lillian with Eleanor. Five years later, to treat her daughter, Eleanor applied to be a nanny for Damien's family, and reunited with Damien and her "deceased" son.