[Amazon Echo Dot] 2nd iPhone in household unable to see Echo Dot in Devices

[TechGuy41]

Plan

Premium - Family Plan

Country

USA 

Device

iPhone XS

Operating System

iOS 12 

My Question or Issue

I have a few Echo Dots setup in my house. My account is able to select the Dots in the devices. When I go to my Wife's iPhone we are unable to select any Dots. They don't show up on the devices even though they are on the same network. 

Is there something that I need to enable on the Dots, or in Spotify to allow her to be able to see them. 

Thanks in Advance.