BT Yev 21b(24) :כולהו אמה̇׳̇ רבתי קרי להו‏ : they call all of them "grandmother" (NB: not just paternal grandmother)
See the entire entry for ˀem, ˀemmā n.f. mother

BT Yev 21b(24)var. :כולהו \אמה̇׳̇ רבתי"{דבי} ביבי קשישא" קרי להו‏ : they call all of them older mother(var.: senior lady) †
See the entire entry for byby n.f. aunt by marriage