Hi :-)
I was skimming through the "families who’ve had the same occupation for five generations" WDQS example from the wikidata newsletter, and saw this odd entry.
I took a look at the articles/references, and those parent attributes for Buffie Johnson (Q21648341) were incorrect - both names are of her teachers, not relatives - Stanley William Hayter (Q641304) and Francis Picabia (Q157321).
I'm just letting you know, in case this indicates a problem with either the tool, or the dataset it was using in that instance. Hopefully you know where to best followup. Thanks!