There is no rule of thumb when it comes to take newborn photos - it's entirely up to you!
You have probably read in many blogs or articles that the best time to get newborn photos taken is in the first 7-10 days after the baby was born. Hands down, the chance that the babies have their eyes closed and sleep through a session is the biggest. But I feel like giving the new parents such a short time frame would put them under another unnecessary pressure.
And what new parents really don't need in their lives is pressure. (Quite frankly, no one needs any pressure.)
As a lifestyle newborn photographer I will come to your home and take your first photos as a new family whenever you want. Some parents do prefer photos where their babies are sleeping like little angles and have their eyes closed. Some parents don't mind or they prefer not to get newborn but baby photos taken instead sometime in the first 3 months.
If the baby is a bit older most likely she will be awake for some part of the session and maybe we get a few smiles or giggles even :)
Don't forget that these photos will be YOUR family photos and will be wonderful memories to look at any time. We don't need to follow any rules or trend. My in-home newborn sessions are relaxed and calm and we completely follow the baby's needs no matter how many days or weeks old they are. We take the photos when they are sleeping or awake and happy and take breaks when they need a feed or just some cuddles.
To read more about my newborn session:
I can't wait to hear from you!