Hi Robyn Murton - There doesn't appear to be any out of the box reports that provide information around a specific user's activity. Although this is type of activity in captured in the analytics system, it is not surfaced in any of the reports.
It is theoretically possible to extract this type of info from a copy of the analytics database, although this enters into the territory of custom development. If you're on Jive 7 or Jive Cloud this would be possible through the Data Export Service, which is powered by the Cloud Analytics system. Here is some technical information on how a developer would be able to extract data from that system: Using the V2 Jive Data Export Service (Analytics)
Let me know if this helps.