I think it's because of how young she appears. Konrad mentioned in the latest chapter that she just turned 12 not too long ago but, when we look at her, she gives off the impression of being around 7 years of age. She's tiny. Even canonically, they've mentioned several times that she's small for her age.
Some of her mannerisms also make you think that she's awfully young~
Yet Konrad, who seems to be very mature than his actual age, feels like he must be somewhere in his early to mid teens. ╮(￣▽￣)╭
Right? But I still love them lol
Oh, absolutely! I totally ship them, and am fully prepared for another ikemen to appear to make my ships a conflicted mess, hahaヾ(❀╹◡╹)ﾉ~
I ship them but I can't help but think that the kid is too young for that lad