Haha it's hard getting photo's of babies I struggle with just the one. Try outside that way lighting will be best or in a well natural lit room. Maybe put six week old in basket with tinsel have 16mth old beside it with Santa hat on??? And give her Christmas baubles to play with taht way it will distract her from poking the baby. If photo's are blurry cos older DD is moving set the camera to sport mode that way it'll increase the shutter speed. HTH