I was going to suggest a big photo as well just because it's easy. Did you write down any quotes or anything during the week? Because you could always do a big quote on one side and then take a new photo or use an older non-Instagram photo of the person on the other side. Or even if you didn't you could add in some familyelated quotes with a generic photo or something. I wouldn't be above taking photos now to use because no one will know it wasn't from that specific week and really it wouldn't matter anyway.
What about a family facts page? With like photos of each person with a list of things like age, grade, faves, etc?