Happy or moody portraits? I'll take both, thank you very much

Do I believe portraits of children always have to be colorful and happy?  No, absolutely not.  Any parent will tell you that their children are not always smiling and jumping for joy.  Children can be serious, pensive, moody, cranky, over-tired, under-stimulated, you name it.  And that's OK.  It's OK if they don't feel like smiling for the camera.  I'd much rather get a genuine serious look than a forced cheesy smile.  When my kids grow up I want to remember all their expressions because there is beauty in every single one of them.