Why is Supergirl Consoling Clark Kent’s Parents at Superman’s Funeral?

And why did the Kent’s travel all the way from Smallville to Metropolis just to attend Superman’s funeral when their own son, Clark Kent, couldn’t bother to show up? And at their old age.

And where is Clark anyway? He should show his gratitude to Superman for saving his life a few times.

[Image from Justice League Episode Hereafter Part I]