I just have to get in mind what the retcon means, so here is Alexis family tree.( geez to geez, her family just got a lot more complicated)
(Voodoo Aligned) Great-Grandmother❦ Great-Grandfather
↓
(Voodoo and Finnish aligned) Grandmother ❦ Grandfather
↓
Aunt - Dad - Uncle - Uncle - Aunt - Aunt - Aunt
↓
Dad❦Mom
↓
(Icelandic Aligned)Twin Sister
(Icelandic aligned)Twin Sister
- Brother -
( Finnish Aligned) Alexis
Her great-grandmother was in Sweden as a tourist at first, then the rash hit. By the time she has a child, the gods have already taken notice, and my grandmothers magic is a bit wonked up. My grandmother has a lot of kids, and none of them have magic. (Maybe their kids do, not touching on that). My twin sisters are born, and instead of seeing spirits, they see the future(possibly why they left? iDK. ) My brother is born- no magic. Alexis is born- she sees spirits.
About the aligned thing, the magic started wonking up. People in Sweden who had "magic genes" , a.k.a Alexis family, lost the attention from the source of their magic when the shrine to ancestors was lost in the Outbreak of 37(long story, look at page 123). But the "magic genes" were still there, just standing around and being junk. So another two generations later, magic starts reappearing (not sure what is so interesting about my sisters that the gods took notice, but here we are).
This is kinda an-off-the-wall theory, but I wanted Alexis to still have a connection to her heritage. And now she is an untrained mage. She has the idea of what magic is about from some of her grandmother's journals from after the outbreak, but her grandmother really got that many encounters with mages, and some of those mages didn't know much either, so she is completely untrained. (if her magic does show itself, her it tires her out alot, and it pretty much always ends in (metaphorical) blood, because runos are a far better way to focus your magic, and because she is taking energy from herself.
Welp, this ended up way longer then expected.