Hello Cheryl,
I've assessed lots of staff meetings for NVQ4 candidates and find the most helpful evidence comes out when the candidate looks at the titles of their optional units and tries to incorporate something on the agenda that would fit at least one of the units (if not more!). For example, if they chose Unit 411 (which is basically about delivering positive outcomes for service users), I would perhaps get the candidate to review with their team, the teams knowledge and understanding of Adult Safeguarding procedures or perhaps look at procedures staff use to safely administer medication to ensure everyone is 'singing from the same hymn sheet'.
An agenda, as Aunty Sue has pointed out, is really important, as is a notice on the wall of your workplace advertising the fact that there will be a meeting and giving the date, place and time of it. A blank agenda could be put on the wall asking for questions or concerns the staff would like raised at the meeting. Then your agenda and the issues the staff want raised could be put on a final agenda for the actual meeting.
Finally, don't forget to explain the presence of your assessor and ask if staff are comfortable with the meeting being observed and documented. Have a copy of the agenda ready for your assessor to put into your portfolio and have a copy of the minutes ready for them too but make sure you don't put any full names on the minutes - initials of the attendees will be sufficient.
Hope that helps and good luck!