I don't think her job needs to be made any more complicated than it is already. Scots has been stereotyped in similar ways - look at Harry Lauder's career as a "tartanface minstrel" - and some dialects of Scots, like Glaswegian and Highland-English dialect, have been useful sources of cheap laughs within Scotland itself for about 300 years (as in the 18th century song "The Massacre of Ta Pheirson"). Maybe somebody with the time and resources for a Ph.D.-sized project could get something useful out of the comparison, but it sounds like a recipe for getting stuck on a gratuitously unwieldy problem.