And although the actress has kept her little one’s details private, she has previously spoken about having children after 40.
“The pressure… about kids, should I have more, and why not, and all that, which is a very loud noise,” she said Elle United Kingdom last April. “Biology is incredibly cruel to women in this decade – that’s the headline, or it certainly was for me.”
Sienna explained that she took matters into her own hands by freezing her eggs.
“After being so focused on needing to have another baby, I figure if it happens, it happens,” she continued. “That kind of existential threat has dissipated.”