Tiana is the second daughter for Hashian, 33, and Johnson, 45. The couple, who have been together since 2007, have a 2-year-old daughter together named Jasmine Lia Johnson.
Johnson is also a father to 16-year-old Simone Alexandra Johnson from his marriage to Dany Garcia.
Johnson and Hashian announced they were expecting another child in December.
“Your crazy dad has many responsibilities and wears many hats in this big ol’ world, but being your dad will always be the one I’m most proud to wear,” Johnson wrote.