wow.. well there is no specific elin quest except part of her death. so i guess for now stick with amity item quests

Also if you don't know this; there is the Red Thread of Faith, you get 3 from china

2 from the match maker. its the most bottom left (?) on the china map under chang'er and her bunny. find an old scholar who will tell you about a couple in the fishing village do what he wants(this requires a lotta walking back and fort). After fight a few ghosts i think they are about lvl 70-90 but they only have around 700-900hp. save the old man and you will get 2 thread

and the other is from chang'an in the forest next to the well enter and a cut scene should start with a boy talking about his "baby" its a frog. do to curiosity you lose it and need to get it back its on the same map. walk to the bottom left of the map and find the frog on a log. careful avoiding buffulos. return the gem to the boy after the frog leaves and you will get a thread

use these on elin (or any other pet). this way she will never run from battle make sure you don't fight things 19 lvls above her or she will break the threads.

good luck lvling her and getting her amity back =3