Thanks a million for your feedback, Lenka!
http://www.mvcr.cz/clanek/scitani-lidu-domovska-prislusnost-... states that “domovska prislusnost” was automatically received a) at birth (where a legitimate child acquires that of its parents or illegitimate child that of its mother) b) marriage (where the wife acquires the one of her husband) c) decision of a municipal authority.
http://www.jewishhistory.cz/cz2/victims/help/domovske_pravo says it was automatically acquired at birth, however in exceptional cases it was possible to grant one in the adult age. Would the context above not be representative of such case?