Mahesh Kumar, a resident of Larkana and brother of the visiting woman Sarala Jewatram Badlani, said the tragic incident occurred when his sister embraced him upon her arrival at the station and started crying.
The joy of meeting her brother after a gap of 16 years was too much for Devi, whose passport was issued from Ulhasnagar, Maharashtra.
She suffered a fatal heart attack seconds later.
Kumar said that her sister's application for visa to Pakistan had been refused four times and this was the fifth time when the application was accepted and she visited Lahore.
Speaking to Geo TV, he said that her family should immediately be given visa to come to Pakistan and take away the body for last rites.
Indian High Commission officials in Islamabad told PTI that visa would be issued on an immediate basis if her brother applies to visit India for the last rites.
"Visas on humanitarian and medical grounds are always issued by us on a priority basis," an official said.