The Proto-Kartvelian word da-
Word da-
Meaning sister

Comments
Heinz Fähnrich, Surab Sardshweladse: Etymologisches Woerterbuch der Kartwel-Sprachen, 1995 Brill

Other words that might be of interest
anc̣₁l ‘elder’, asul ‘daughter’, c₁ol- ‘wife, sexual intercourse’, c̣₁ul ‘baby, child’, deda ‘mother’, ḳ̣ac ‘man, male, husband’, ḳ̣uṭu ‘boy, penis’, mama ‘father’, š(e)w- ‘to beget, lay eggs, child’, Ʒ₁am- ‘brother’