Without more context from the specific fanfiction, it's hard to say exactly who Leah is. She could be an original character created by the fanfiction writer, perhaps someone with special powers or abilities.
One great 'Annabeth Chase and Magnus Chase Fanfic' is 'The Chase Siblings' Adventure'. It has an interesting plot where Annabeth and Magnus team up to solve a mystery that involves both Greek and Norse mythology. The characters are well - written, staying true to their original personalities from the Rick Riordan books.
Leah, in the Bible story, was Laban's daughter. Jacob worked for Laban for seven years to marry Rachel, but Laban deceived him and gave Leah first. Leah was in a rather difficult situation. She had to compete for Jacob's love with her sister. Despite this, she played an important role in the family and the continuation of Jacob's lineage as she gave birth to several sons.
Leah was one of the wives of Jacob in the Bible. She was the older daughter of Laban. Leah was not as favored by Jacob as her sister Rachel in the beginning. But she was very fertile and gave birth to many sons for Jacob, which was highly regarded in that patriarchal society.
Well, it depends on various factors. Sometimes such stories are a mix of truth and imagination. We might not have all the details to determine its authenticity completely.
Some Tumblr blogs are dedicated to Rick Riordan's works and might feature or recommend 'Annabeth Chase and Magnus Chase Fanfic'. You can search for relevant tags on Tumblr and explore the blogs that pop up. Just be sure to check the blog's credibility and the quality of the fics they promote.
I don't know who the author of 'the angel's chase a chase fulton novel' is. There's not enough information given just from this title to determine the author.
I'm not entirely sure as the 'grunt story' isn't a widely known mainstream narrative. But generally, Leah Clearwater and Jacob Black are characters from the Twilight series. Leah is a werewolf and has her own complex relationships within the werewolf pack. Jacob has his own story arcs involving his love for Bella and his role in the werewolf community. Maybe in this 'grunt story' there could be some specific adventures or interactions between them that are unique to this particular telling.
I'm not sure which specific 'Leah' in 'American Horror Story' you are referring to. There are many characters in the series, and without more context, it's difficult to identify a particular Leah.