If you've entered your Google Analytics or Facebook Tracking Pixel in your account settings, widgets will be tracked in addition to other events like quotes and bookings.
You can find more details on connecting Google Analytics and what is tracked in our Tracking guest interactions through Google Analytics and Facebook Pixel article.
The widget embed code will automatically match Google Analytics clients on the parent page if possible, to track the sessions across page domains. However, note that if third party cookies are blocked by the guest in their browser configurations, sessions will not be able to be tracked across page domain. Instead, there will be three separate sessions -- one on the containing page, one in the widget, and one on the quote reservation page.
If you are embedding GA on your own site, make sure to set the SameSite=None flag on the GA cookie so that the cookie from your site can be used by the widgets and reservation form as well:
The OwnerRez hosted website and widgets will set this flag automatically.