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

Expressions researched:
"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"

SB Canto 4

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.

SB 4.28.45, Translation and Purport:

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.