I was blessed with only one child, but I've always said if God saw fit to only give me one,he (my son) was the one to give me.
His dad and I split up when he was 2. Much time together on our own. We got to know each other very well. When he left I had no buffer just an abyss. Thank God I took alot of pictures. I use to be a photographer so I was geared to that.
Without those pictures my menopausal brain wouldn't remember much. Maybe when you all get together at a holiday gathering, put a tape recorder (sometimes less invasive than a comcorder)in the middle of the table and direct the conversation to reminiscing. I did it with my grandfather and my dad on their 75ths. To hear my son at 5 and then at 26 in the background laughing and asking them questions is priceless.
Hopefully even the memories of your children who have passed on will be uplifting in its own way and make up a bit for the pictures you don't have.