I do kinda agree with that view, but also think of it like this, the longer she is around him the more she would fall form him again. It is a lot more painful to stay with someone you know you can’t be with, then you would have to let them go off with another person. In the end it is more of the fact that she wants to save herself from the heartbreak.
I honestly think the best course of action is to slowly distance themselves... AND EMPHASIZING THE FACT THAT THEY ARE JUST FRIENDS. IF I WERE HER I'D TELL HIM AND EVERYONE AROUND EVERYDAY "LUKAS IS MY KIND FRIEND" "I HAVE A FRIEND NAMED LUKAS" "LUKAS MAKES ME FEEL LIKE I HAVE A YOUNGER BROTHER." "YES, SINCE WE ARE FRIENDS AND NOTHING COULD CHANGE THAT FACT."
UhM she shoulda followed the original route so he'll forget about her. Distancing herself makes it worse since manga boy mentality is "Omg shes ignoring me now?! I'll make her notice me one day! ヽ(`Д´)ノ". Little hero is an innocent kid and she already making him go another route if she keeps this up smh.