Newborn dark skin

Hi all. My husband and I have been thinking why is our second born dark skin. We are both fair, so is our first born. Of course this is our child and we love her so much, just curious cos we don't know if her skin colour will change or why is she diff from us. Nevertheless, she's still our precious and we love her. Pls advice if u have been in similar situation. Dont send me articles pls. Thank you.