the sister could not possibly have understood it. Even the wording. There are not two generations overlapping, but 2 groups in one generation. (wt double talk). Then, wt also teaches that the generation WILL pass away, not like"jesus" said will NOT*** pass away.
***wt teaches that the anointed will be all gone from the Earth before he destruction. "jesus" said they would survive, (or not pass away)- and did!, - in the primary fullfillment, Jerusalem 70 CE