Another theme might be power and politics. Given her background, fanfics could explore how she navigates the political landscape. She might be vying for power, or trying to protect her family's interests in a world full of political intrigue. There could also be themes of self - discovery, where she learns more about herself and her capabilities outside of what is expected of her in the original story.
I'm not sure of specific 'oc alys karstark fanfic' off the top of my head. But you could join relevant fan communities, like on Reddit or Tumblr. Fans there might be able to point you to some great ones. They often share and discuss their favorite fanfics.
There could be. A lot of fanfic writers are drawn to the Starks and the Karstarks in the world of Westeros. They might create interesting storylines where Oc Stark and Alys Karstark have adventures together, or perhaps a romantic relationship that develops against the backdrop of the political intrigue in the North. You might have to dig around a bit to find the really good ones, though.
One common theme is loyalty. Given the importance of loyalty in the Stark and Karstark families, fanfics often explore how Oc Stark and Alys Karstark uphold or struggle with loyalty to their families and each other.
One possible plot could be that they marry for political reasons at first. Jon, being the Lord Commander or having some power in the North, and Alys, coming from the Karstark family, their union could strengthen the North's stability. As they get to know each other, they develop real feelings. They might face challenges from other noble families who are jealous or see their union as a threat. They then have to work together to overcome these political and social obstacles.
You can try some popular fanfiction websites like Archive of Our Own (AO3). There are likely to be various stories about this pairing there. Just use the search function and type in 'Jon Snow married Alys Karstark' and it should show relevant works.
First, draw a long and curved line for the cat's spine to show the stretching. Then, draw the extended legs and paws. Add the head and ears, and don't forget to give it a cute expression. For the fur, use short strokes to create a fluffy look.
It's a fantasy adventure story with lots of exciting twists and turns. The main character, Ivantill, embarks on a dangerous journey to save a magical realm.