Why fight it? Sometimes cute little kids decide they don't want their picture taken. You can't really blame them. Even adults fight it. Family portraits would often be missing the "male presence" if wives and mothers let guys out of it. So photographers shouldn't be too surprised when pictures don't turn out like they dreamed when children-of-will are involved.
Case in point:
I said, "Hey, let's get a shot of just the kids! Brinlee and Chandler, you guys stand there together and we'll let Chandler hold the baby when you get set."
I actually thought this was a better group of pictures than the posed kind I dreamed of originally. It shows the personalities of the kids and how much fun it is to work with them. I love these little children!