Asked about reports that her son had been hitting his wife, she said: "Only the police know what happened, what do we know? We are continents away."
"As a mother with just one son, what can I do?" she added, "we are completely finished. We are now left with no support."
She also said she didn't know there had been allegations of violence and abuse, as reported by Harshita and her family.
Northamptonshire Police have not confirmed if they are in contact with authorities in India, where Mr Lamba is believed to be.
Indian police have said they have not been able to launch an investigation as the crime took place in the UK.
Mr Lamba had been living on a student visa in the UK. He and Harshita had an arranged marriage and were wed in March in India before moving to the UK in April.