I think it came out in the 60's. It had either both or one of the
child actors from "Mary Poppins". All I remember is that the boy (or
girl) fell out of a window and died or was gravely injured. I already
checked IMDB and did not find it in the actors past films. I think the
film was about christmas miracles??

  Please help again!!

I think you're looking for "Pollyanna," from 1960.  It starred Hayley
Mills, a British child actress who appeared in quite a few Disney
movies from that period (but not "Mary Poppins").  While not about
Christmas, it is relentlessly about hope and happiness and all sorts
of sugary sentiments.  Near the end she falls off the roof and is
seriously injured.