The Growth team maintains the Mentor dashboard. One of the dashboard's modules is Mentee overview, which allows mentors to see various informations about users they are assigned to as mentors, such as their editcount, blockcount and similar.
As part of T297811: Mentor dashboard: Show information about mentees' pending changes on FlaggedRevs wikis, it was suggested to tell mentors how many unreviewed edits each of their mentees have, as a new column in the module. This would look like this:
The link from the number could then lead to Special:PendingChanges, filtered to include only edits from that particular newcomer.
- At FlaggedRevision-enabled wikis, Special:PendingChanges has a field "username", which allows users to filter the revisions by username.