Some of the late Princess’ German ancestry is recorded. The first ‘von’ appears at the eighth generation of her ancestors with Sabine von Kapff (no parents given).
The next is at the ninth generation, Anna Maria von Molsdorff (no parents given), mother-in-law of Sabine (their husbands, father and son, were both named Daniel Maier).
For what is recorded back to the 20th generation with only two known ancestors there are no other people with ‘von’ in their name. It isn’t an absolute indicator of nobility but there are few German nobles without ‘von’ or ‘zu’ in their names. I am not sure that Kapff and Molsdorf are noble... perhaps just villages were those families come from.