You can change the name of your Apple Watch by following these steps:
- On your iPhone, open the Apple Watch app.
- Tap the My Watch tab.
- Tap General.
- Tap About.
- Tap the current name of your Apple Watch.
- Enter the new name, then tap Done.
- Make sure in icloud, Apps using iCloud, Watch is checked green.
If you have already done these steps and the name is not updating on your iPad and iPhone, it could be that the devices are not connected to the same iCloud account, or they are not connected to the internet. Make sure that all your devices are connected to the same iCloud account and have an active internet connection, then try changing the name of your Apple Watch again. If the issue persists, you may want to try restarting your devices and checking for any updates.