does Siri recognize more than one voice

Siri is personalized, so no she will not work with a different user on your device.

Yes you can set up Siri again by doing the following:

1. Go to Settings.
2. Tap Siri & Search.
3. Turn off Listen for "Hey Siri," then turn it back on.
4. When the Set Up "Hey Siri" screen appears, tap Continue.
5. Say each command that you see on your screen.
6. Tap Done.

If "Hey Siri" isn't working on your iPhone or iPad - Apple Support