I was low-key joking about this ship being the equivalent of "two people locked in a room can't leave until they x" but this kid just soft checked Sherbets feelings with the couple question (although it really just makes her sound like the person who killed that other couple with the whole "as well" part. If she did, they weren't human because of how she specifies she's never killed a human...or at least she didn't see them as human.)
Then she tries to get our resident Tsundere to admit she cares if Sherbet is killed, and then says something that could be intended to inspire jealousy. If this author isn't simply pulling out every contrived "side character nudges the main couple" card in the deck, then this is starting to feel like less of a crack theory lol