Iām not aware of any way to do this on a per-rule basis. You would need to use different mobile presence sensor devices, each configured with a different size geofence. While itās not possible to do this with the hubitat mobile app, there are other mobile apps that be integrated with hubitat to do just that. In other words with a single mobile phone, you can have multiple geofences (but youāll need other apps installed on the phone to make this work).
See this post from another recent thread for a slightly more detailed description of how that works.
You will need to create a guest account at portal.hubitat.com for your wife, login to the mobile app with that account on her phone, and select the option to create a new presence device when logging into the app.
This article from the hub documentation explains how to create a new guest account.