Sebastianus was named “Chałupnik” sometimes, but it was rather his status than family name. “Chałupnik” means owner of house and priests have used this form very often to unrelated people, especially in XVIII century.
Sebastianus was named also “Duda” mainly when he was a godfather. Cunegundis was named “Chałupniczka” (= wife of “Chałupnik”) or “Dudzina” (= wife of “Duda”).
It is very likely that all Cunegundis from Drogoszewo named as Chałupniczka, Dudzina or Feledzina/Felodziakowa is the same person. Name Cunegundis was more popular in XVIII and XIX centuries than nowadays, but it was quite uncommon in comparison to other names e.g Antonius or Catharina.