Personally I would stay away from WiiM and the Unison as the both lack USB local play (there is no substitute.) Although when the network goes down (as it seems to weekly around here) nothing can be controlled with ANY "network" player. You might want to find something that adds Bluetooth so she can at least listen to Spotify from her phone during those instances.
The iFi looks like the best value but I only have a Bluesound, Allo USBridge Sig/Shant and a RasPi/iFi Elite in the budget space, so I can't comment on it's functionality.