By (re-)evaluating the etymologies of the three Proto-Germanic kinship terms *aiþīn-/-ōn- ‘mother’, *aiþma- ‘daughter’s husband’ and *faþōn- ‘father’s sister’ that are all claimed by at least some etymological handbooks to be nursery words or hypocorisms, I contend that we must abandon their nursery-word interpretations and rather regard them as inherited words derived from known Indo-European lexical material in a way that reveals important information on the Old Germanic society and its family pattern.