Dalbir Kaur, who is fighting for the release of Singh who is languishing in Lahore's Kot Lakhpat jail for over 20 years, met Gandhi at her residence and raised the issue.
Maintaining that she cannot express the pain the family has suffered, Kaur said that Gandhi listened to her patiently and assured all help.
49-year-old Sarabjit was convicted and sentenced to death for alleged involvement in a string of bomb attacks that killed 14 people in Punjab in Pakistan in 1990.