The Sweet Home Alabama star welcomed the newborn with husband Jim Toth on September 27.
Sources tell People that the new addition to Witherspoon's family is fitting in nicely, explaining: "Everyone is bonding with the baby. And Jim has had a lighter workload and has been spending a lot of time at home with the baby as well."
The source added: "[Reese] definitely feels settled in her family life with Jim and her kids. They can't wait to start life with their new baby."
Witherspoon was recently spotted in Santa Monica, California on Wednesday (October 3) with baby Tennessee, eating at local restaurant Huckleberry.
The 36-year-old actress also has two children, Deacon and Ava, from her relationship with Ryan Phillipe.