Your best bet is to create a dashboard page with those reports and send them a link to that dashboard. The reports will not be contained in the email but if they click the link it will show all of them at once. Might be good enough for them.
I know that isn't perfect but I don't believe it is possibly to send multiple reports in one email cleanly. You can technically send a copy of the record that triggered a notification. If that form contained several embedded reports they would get these displayed in the email. I tested this on a form with more embedded reports than sanity should allow, I could see them all. I'm just unsure how it picks the form to use on the table(maybe the form that contained the triggering field? Or the one the user was on, if a user triggered it) so there are questions that need to be answered. But.. maybe it would work for you and you can run with it or someone knows more than I do and they can help you here.
