It reminds me of my daughter. I cry every tome I hear the opening notes, and Im sobbing by the end of the first chorus.
Gone Away- Five Finger Death Punch also gets me teary (I know its a cover, its just more in line with my musocal tastes)
Little One by Highly Suspect is also a song that brings Harper to mind, its more of a song written to a lover, but it isnt overtly romantic, almost platonic so it fits well.
If I wasnt pressed for time (Im working atm) I could find some more from my childhood but these are the ones that hurt most today.