There was a manga series I had some years ago. Thought the title was Sarah or somthing similar, but not showing up on searches.

Mature rating. It was set in the future. Some plague affects all people, after they become adults it is only a matter of time before they either die or mutate into monsters. An organization has gathered young girls who are apparently super powerful, trained them to fight, and send them out on missions, ultimatly to find some undamaged DNA to help restore the human race. They all wear some kind of maids outfit. The main character I believe is Sarah, usually accompanied by a shorter blond girl, her partner.

Violent, cannibalism is featured in some stories, might be considered supernatural since some of the mutated monsters fall into the lines of mythical legends.

I haven't read them, but maybe Korokoro Soushi or Kono Sekai no Owari e no Tabi?

Nope, none of those

It is strange because I had the set, or most of them, and now I can't find it listed anywhere