A: "Is it possible to have multiple sheets for multiple websites?
One Sheet for Site A, another sheet for Site B"

- yes of course it is possible

you can use a separate google sheet for each site
not only for two A and B but also for C, and any number of websites
just create a separate widget for each site and attach a google sheet for each widget in a widget builder

there are two use cases:
* the first is - to use one Google sheet for two widgets(you can find this two tabs below in the master google sheet ) (currently two widgets are available, but then we are already working on several new ones like reviews, call-to-action buttons, welcome bar and so on)

and the second you can use for each individual widget and each site a separate google sheet as you described