The lighting was simple, a single Nikon SB-800 in a 24" x 24" softbox, set to 1/16th power and triggered by a pocket wizard.
While we were shooting the baby started to cry and the family dog become concerned and just had to check on her, which is my segue to the following tip:
When shooting certain situations (like babies and weddings) it's a good idea to keep the camera close to your face because things can happen quickly (a yawn or a dog checking on its baby) and if you have the camera at your side you just won't be able to get it to your eye quick enough.