Basically the HPAU version of The Blood of Gods Run In Our Veins  (This is Percy Jackson AU SNSD oneshots/multishots. mostly taengsic as of now)

1. (WARNING DARK ish) The Blood of the Covenant is Thicker than the Water of the Womb - Jeti - Jessica and Tiffany are in their seventh year at Hogwarts and everything is a mess. Harry Potter has disappeared and Voldemort is on the rise again. Jessica's parents are both Death Eaters and they want Jessica to join them and stand next to Voldemort as he takes over the wizarding world. Set during the Deathly Hallows/Battle of Hogwarts. One shot. Finished. 

2. Princesses and Happily Ever Afters - Jeti - FLUFFFFFFFF Tiffany falls in love with Jessica because Jessica is a princess and Tiffany had a thing for princesses since she was a kid. One shot. Finished. 

3. The Girl From Durmstrang - Jeti - Jessica transfers from Durmstrang to Hogwarts in her fifth year. Things are a little rough but it gets worse in her sixth year when Hogwarts decides to host the TriWizard tournament and her friends from Durmstrang show up. Her loyalties are tested. Can she avoid being called a traitor to both of these schools?

4. Love is Magical - Jeti - Jessica is a witch. Tiffany is not. They were best friends until Jessica left Tiffany after her 11th birthday to go to a "boarding school." Tiffany begins to feel left out as Jessica makes new friends. For some reason she can't shake the feeling that her best friend is hiding something from her.  

Or

A witch and a muggle fall in love.

 Love is Magical - extended summary - Jessica and Tiffany were the best of friends. They did everything together ever since they were six years old. Tiffany radiated warmth and was always a bubble of sunshine, laughter, and hugs. Jessica was more quiet, too shy to talk to anyone other than Tiffany. Tiffany had many friends while Jessica only had Tiffany, but to Tiffany, Jessica was the only person that mattered. Tiffany thought they would be best friends forever, always just the two of them. At least that's what she thought until the summer after Tiffany’s eleventh birthday, Jessica told her she was transferring schools.

Though Tiffany didn't understand why Jessica was leaving school, why Jessica was leaving her, she couldn't do anything. Promising to keep in touch, Jessica reassured Tiffany that they would still be best friends. Tiffany believed her but Jessica never returned her calls, texts, or emails. She's firmly believed her friend had forgotten her until one day she received a letter addressed to her from Jessi. Afterwards, they continued to send each other letters. If Tiffany thought Jessica was being vague whenever Tiffany asked her school was going, she never mentioned anything. Eventually, Jessica comes back for the summer and the two hang out like nothing had changed. This continues for a few years and Tiffany is fine with her relationship with Jessica. Jessica is the same broody, reticent, blunt girl she knows and loves and Tiffany is sure she is still Jessica’s number one. Everything changes however, when they turn sixteen and Jessica doesn't come home for the summer alone. Instead, she's brought a couple of school friends. Seeing Jessica interact with her friends from school, Tiffany realizes she doesn't really know Jessica at all and finds herself burning in jealousy all summer. Has she lost Jessica? Why does she feel that Jessica is hiding something from her?