My best guess is "Beware of the Brothers!" where FL was adopted into a family for having a crazy resemblance to their lost or dead younger sister, travels 20 years back in time and (spoilers) her step brother is the ML.
I read it, and all of the men on her family are weird... But it doesn't seem like they're romantic interests??? Where'd you get it that her dad is the ML? marinchan
They got that from the novel that the manhwa was adapted from, it's pretty well-known that the father is her true love and the brothers are also love interests
IM SEEING THE ROMANCE TAG AND IM SCARED BC ALL I SAW WAS HER FAMILY
im traumatized from that one manhwa...........