ET's Katie Krause spoke with the 'Open Book' author at the 2020 Create & Cultivate conference in Los Angeles.
The couple welcomed their first child together on Saturday.
The singer's father, Gary Trainor, is currently in stable condition.
Madden and Diaz welcomed their first child together at the end of last year.
The couple is already parents to a 3-year-old son named Asher.
This will be the actor's third child.
The 24-year-old country singer has married songwriter Josh Kerr in Nashville, Tennessee.
Miller also opened up to ET about undergoing a facelift with plastic surgeon Dr. Payman Simoni.
The late L.A. Lakers star has been remembered in murals, light installations and more.
Abby Lee Miller has no issue sharing all the details when it comes to her recent facelift.
Abby Lee Miller stopped by ET on Friday to guest co-host the show.
ET's Keltie Knight spoke with the longtime talk show host at his star ceremony in Hollywood.
ET is breaking down everything fans need to know before the memorial service on Feb. 24.
ET sat down with the actor alongside his 'The Way Back' co-stars and revealed the qualities he's looking for in his next relationship.
