Spoiler
She is paired with aseph but it just doesnt show on him yet cos his soul is corrupt.
if you read the previous chapter wherein the crown prince made a comment about her crest, he said something within the lines of, "her crest feels different" and judging by the color of the goddess' speech bubble, it seems like her magic crest symbolizes the fact that she is the goddess' favorite child. However, i'm quite confused as to why she still feels the symptoms of not being able to meet your fated pair even though it's likely that she isn't paired to anyone.
my guess is that her pair is Aseph. But i feel like they have to somewhat break the cycle first before his mark appears. Because it has been told that they're in a loop wheren Zay meets an undesirable end, and everytime she attempts to save him, Aseph ends up selling his sould to devil out of jealousy. They need to break free from their "supposed" fate first and create their own fate. just a theory ╮(￣▽￣)╭
AND THAT'S JUUST A THEORY!!!! A WEBCOMIC THEORY!!!!!
if the goddess likes her so much, why did she pair her with someone that she doesn't want instead of with aseph?