SB 4.28.45

ajānatī priyatamaṁ
 yadoparatam aṅganā
susthirāsanam āsādya
 yathā-pūrvam upācarat
ajānatī — without any knowledge; priya-tamam — her dearmost husband; yadā — when; uparatam — passed away; aṅganā — the woman; susthira — fixed up; āsanam — on the seat; āsādya — going up to; yathā — as; pūrvam — before; upācarat — went on serving him.
The daughter of King Vidarbha continued as usual to serve her husband, who was seated in a steady posture, until she could ascertain that he had passed away from the body.

It appears that the Queen did not even talk to her husband while serving. She would simply perform her prescribed duties without talk. Thus she did not stop rendering service until she could ascertain that her husband had passed from the body.