I am not a pro by any means, but..i'll comment on stuff besides lighting
#1 needs more room around the frame, more head room and don't cut the hands off. It's a good pose and a great angle. I would have just swapped the mother and the father around so the mother covers up his largeness more.
#2 too much head room, too much of the bodies are cut off, there is a shadow across the right girls face
#3 good composition.. watch that hand though, it looks disconnected and like its choking him, also if you break the rule and still do that, make sure the fingers are flat and together
#4 if going for a straight forward picture as you did, do center it as best as possible. you could have tried for more interesting posing, like having the mother stand up slightly behind the father with her hands on his shoulder, wedding ring showing of course 
#5 a cute snap shot, but not well posed, not to mention the guy on the left has a horrible expression lol, i suggest looking up the rules on posing, though those can be broken, again with the space issue too.. more room on the sides, should have been a horizontal picture
#6 not a bad choise of pose, but the leaves break the picture
#7 i like the feel to this one better, good use of space, the staggered heads, mom in the middle, it's just they all have double chins and though a good picture, i'm sure the mom isn't going to like it, i would have maybe sat them together in the leaves and shot down at them
#8 good picture, nice composition 
hope this helps! off to a good start 