Common knowledge within the newborn photography community is that newborn photo sessions need to be done within the first 14 (or even first 10) days. There are many reasons for this. Having come from a quite a small environment recently, they are able to curl up into those adorable curly and squishy poses with ease . Also newborns at this age tend to fall asleep and stay asleep, leading to a smoother and faster session.
That being said, sometimes parents do not come into the studio within the first two weeks. Perhaps they didn't know newborn photos needed to be done so soon. Mom may have had a rough birth and is just trying to recover. Maybe the thought of packing up their baby and heading out of the house so soon is just too overwhelming (I know it was for me!). Whatever the case may be, does it mean they missed their opportunity? Absolutely not!
With patience and appropriate expectations (and a lot of milk!), I have successfully photographed newborns up to 7 weeks. We wrap them up, we can take family and sibling photos, we can capture the little details and more often then not, we can get those sleepy bean bag poses.
Yes, it is easier when newborn babies are only a few days old. However I could never deny a family beautiful newborn photographs because their baby is outside of the ideal window.
See baby girl at 4 weeks old as an example.