Add a second router to my U-Verse router

Hi, I have an NVG589 router and it carries voice and internet only. No TV. It works great, strong, no dead zones. I want to add a second access point (second router, separate SSID) for my kids. I want to be able to change passwords, add parental controls, etc. without impacting my and my wives devices. I have an Asus RT-AC52U that handles these things great. Any way to do this? Thanks