The top photo is from an ad for Albert Nipon, the Philadelphia-based (yes, Philadelphia-based) fashion design firm started by the designer of the same name. Nipon's namesake brand was one of the most popular fashion brands of the early eighties, coinciding with Ms. Donahue's reputation as one of Elite's top new models.
The photo below is from a DeBeers jewelry ad, from 1983.
Nancy Donahue defines her own style as "innocence and cool sophistication." This picture (like the one above) sums up that definition perfectly. :-)