Someone missing from our photos

Every time I look at a picture of my children there is always an ache in my heart because someone is missing. That someone is Samuel. I can't help myself. The picture is not complete. There should be four children there, not three. He should be on Alex's lap or sitting next to Jacob. He should not be missing from the picture. That is not how it is supposed to be. I pictured my family of four children so many times in my head. I dreamt of what it would be like for Michael and Alex each to have a baby to hold, not one baby to pass back and forth. I saw my twins together playing on the floor. I saw myself holding them on my lap...I could actually feel what that was going to be like, rocking them together in a rocking chair. Two highchairs, two cribs, me tearing my hair out as I chased after two boys. How could I have pictured it so perfectly? How am I living a life so different than the one I pictured?