I get HA to ask my iphone where it is using the find my phone feature. I use automation to request my iphone location based on time of day, battery level or when i need to confirm location. It might be helpful as an alternative to the HA ios app for your wifes phone.
Another alternative is to use homekit automation on your wifes phone to turn on a HA switch (through home bridge) when she is not home. This might be more reliable than the HA ios app.