No ringtone sounds on my iPhone when I get texts from my wife...


I have set the ringtone default for everyone to "Circuit" so I don't miss them! I get the sound from everyone's texts, except those from my wife. I've looked in the Settings and there only seems to be a setting for phone calls. In the Contacts I have her text tone set to "Default" and texts from her phone don't sound. I changed it to "Circuit" and it's still silent. We have tried changing settings on both phones but it's still the same. Her texts make no sound on arrival. Everyone else's do.

What have we missed?