I like 1-3 and 6-9 a lot.
I would be happy with the results if I was you.
These are very good in my opinion considering you are just getting into this type of thing. :thumbup:
Very good sharpness/color/contrast all around.
This is what I would expect from that lens though, so anything less would be a problem.
I know you are good at editing, and I dont think much could be done in post to improve these.
4 & 5 I find to be distracting, because its like there are 2 subjects, but only one is in focus.
You can't help also looking at the subject OOF (kids, or parents), and it just doesnt work for me.
I might have tried the same thing, because I am a noob with these types of shots.
I also find the lighting to be lacking in 4 & 5.
Were you using a flash diffuser for these?
I think it may have helped with what others are saying here. I would have to admit that the light is slightly "harsh" on many of them.
What may have also helped is if you turned down the flash power slightly.
Overall though you probably made the right choice using the flash, and not doing so would have been even worse in my opinion.
Hope this helps.