I. Why the combination is common
The combined name is statistically banal because both halves were, separately, very common at the same time. The forename Jennifer rose sharply in the United States and Britain in the 1960s and 1970s and was the most-given girls' forename in the United States from 1970 to 1984; the surname Cunningham was, by the same period, one of the more common Scots-origin surnames in Ireland and a settled name across the wider Anglosphere. Any forename in the top ten of its decade combined with any surname in the top fifty of its country produces the same pattern: many bearers, distributed widely, with no shared identity.
Genealogical and electoral indices return several hundred living Jennifer Cunninghams in Ireland alone, and several thousand across the United States, the United Kingdom, Australia, Canada and New Zealand combined. The combination is not, in any meaningful sense, anyone's name in particular.
II. Distribution by country
Within the Anglosphere, the highest concentrations are in the United States (very large absolute numbers, modest density), in the Republic of Ireland and Northern Ireland (small absolute numbers, very high density given a small population), in Scotland and the north of England (the surname's older heartland), and in Australia and New Zealand (carried by emigration in the nineteenth and twentieth centuries). Bearers also occur in modest numbers in Canada, in the West Indies, and across the imperial professional and commercial diaspora more broadly.
Within Ireland, the surname's heaviest historical concentrations are in Donegal, Down, Antrim, Galway, Roscommon and Mayo. Bearers of the combined name therefore occur disproportionately in those counties relative to a uniform distribution; but the absolute density is everywhere modest.
III. What the combination signals
It signals very little. A late-twentieth-century anglophone forename and a Scots-origin surname together suggest a bearer somewhere in the Anglosphere born between roughly 1950 and 2000, with a family history that probably touches on Scotland or Ireland at some remove; that is the entire informational content of the name itself. Profession, place of residence, accomplishments, opinions, identity — none of these are signalled.
This is, of course, the ordinary condition of all common personal names. They are markers, not descriptions.