The Notify for Xiaomi & Mi Fitness app has a Home Assistant integration.
This would work with your Redmi Watch Active 3. For your wife’s Miband 3 she can use Notify for Mi Band – Apps on Google Play
If either of the watches can install the ZeppOS Home Assistant app then it can sync info: Home Assistant companion for Zepp OS devices - Share your Projects! - Home Assistant Community
The Passive BLE Monitor component supports some Xiaomi smartwatches: GitHub - custom-components/ble_monitor: BLE monitor for passive BLE sensors
Lastly using ESPHome presence detection might work: ESPHome BLE tracking Mi Band 4 - Working