ABANDONED. Fantasy father needs to kill daughter to live forever and half sister goes missing

[Nikki]

Im looking for a book about a girl with a dad named Lucian who has to sacrifice one of his children in order to not age and then her little half sister goes missing. She goes looking for her while her father looks for her for the sacrifice. The half sister was 4 and name started with an M I think.

[Lobstergirl, au gratin]

When did you read it or when was it published? Children's, YA, or adult? Any cover art? Author male or female? Series or standalone?

[Kym]

Finding Meara by Lara Schiffbauer ?

[Lobstergirl, au gratin]

Nikki, was Kym's suggestion your book?

[Lobstergirl, au gratin]

Lobstergirl wrote: "Nikki, was Kym's suggestion your book?"

No response in 2 years. Moving to Abandoned.