Valkyrie was born in 1981, but, three problems:
- She married Evan in 1993.
- When they first met, her Taint had already fully matured.
- Ilina was born in 1994.

So how should Kim retcon this, d'you guys think?

So it goes like this: Valkyrie is born in 1981 and she'd be 13 in 1993 and if Ilina was born in 1994, she'd be 14 if she gave birth to Ilina. You could go three ways about this:
1) You could keep it as is while adding that Valkyrie regretting giving birth to a child at such a young age and that doing so was irresponsible.
2) Make it so that Ilina simply misremembered her own birth due to being stuck in that brainwashing machine (itself a result of a retcon) for 2 years.
3) Retcon nothing because according to the LSP wiki you created, Ilina was born in 1996 (which means Valkyrie would be 16 if she give birth to Ilina, which is still a bad idea) which solves your problem anyway.
([size=78%]https://lsproject.fandom.com/wiki/Ilina_Horton[/size][/size][size=78%])[/size]