The meeting within 14 days of an election is scheduled because councillors have to sign a declaration of acceptance of office within a period (can't instantly recall the period without checking), in the absence of which the elected councillors cease to be elected and a new election must be held. If too few councillors were elected for a meeting to be quorate, it is usual for those that are elected to sign their declaration of acceptance of office anyway (it has to be done in front of the clerk as Proper Officer but not necessarily in a meeting) whilst arrangements are made for appointments by the county council to enable the parish council to function (they have the power to fill vacancies until such time as a fresh election or co-options can be made). So, whilst your parish council hasn't had a meeting within the 14 day period, it's not necessarily an issue and certainly not one the external auditor would comment on unless there are other circumstances at play here.
Not all parishes meeting monthly or indeed even bi-monthly and I am aware of very small parishes that meet quarterly to meet the requirement for a minimum number of meetings each year.