aqwsed12345 : To assess the plausibility of a familial connection
to Pope Benedict XVI (Joseph Ratzinger), it's pertinent to examine the geographical
proximity of Weilheim to the birthplaces of the Pope's maternal ancestors.
Geographical proximity would only be relevant if we knew that Katharina Blabst's mother, both her mother's parents, and all four of her mother's grandparents were born in Weilheim in Oberbayern, Bavaria. We know none of that. We only know where her mother was buried.
Consider the full spread of the Pope's maternal ancestors to see how location can change over a couple of generations.
Maria Peintner Rieger (Joseph Ratzinger's mother) was born in Muhlbach bei Oberaudorf, Bavaria.
Her mother, Maria Tauber-Peintner, was born in Raas, South Tyrol, Austria.
Her father, Isidore Rieger, was born in Welden, Augsburg, Bavaria.
Her maternal grandmother, Betty (Elizabeth Maria) Tauber, was born in Maehrisch-Weisskirchen, Moravia, present-day Czechoslavakia.
Her maternal grandfather, Anton Peter Peintner was born in Aica, South Tyrol, Austria.
Her paternal grandmother, Maria Anna Rieger was born in Welden, Augsburg, Bavaria.
His paternal grandfather, Johann Reib was born in Untergünzburg, Bayern, Bavaria.
If Joseph Ratzinger's maternal line was so widespread over three generations, it seems quite likely that of Stefanie Brzakovic would likewise be widespread. So with geographical proximity there are no fixed points to measure.
One other gem that I picked up was that Betty (Elizabeth Maria) Tauber, the Pope's great-grandmother, was the daughter of Jacob Tauber (b.1811) and Josefina Knopfelmacher (1819-1886). Josefina Knopfelmacher's nickname was "Peppi". I can only think that this gives credence to Stefanie Brzakovic's recall of Joseph Ratzinger's nickname.