Пока они с братом обсуждали, какую

Пока они с братом обсуждали, какую мебель купить в гостинную, пришла мама

Результаты (английский) 1:

While they discussed with his brother what furniture to buy in the living room, mom came

Результаты (английский) 2:

While he and his brother were discussing what to buy furniture in the living room, my mother came

Результаты (английский) 3:

while he and his brother were discussing what to buy furniture in the living room, mom comes in