In most comic storylines, Jimmy Olsen isn't a guardian. He's more often involved in reporting and assisting Superman rather than having a guardian role.
One common theme is the power struggle. Given the nature of the Continuum world, there are often power dynamics at play between different groups and Kiera and Alec are right in the middle of it in many fan fictions.
I'm pretty sure it's not real. There's no concrete evidence or reliable source to confirm its authenticity. It could just be a story someone came up with for entertainment.
One of the well - known works in Kiera Cass's Fantastic Fiction is 'The Selection' series. It features a unique concept of a competition among young women for the prince's hand in marriage. The series has engaging characters and a captivating plot that keeps readers hooked.