Ahead of husband Prime Minister Kevin Rudd's arrival in India yesterday, Ms Rein visited three- and four-year-olds at a kindergarten in Mumbai's Dharavi slum, the biggest in Asia.

Dharavi is home to one million of Mumbai's poorest, making it one of the most densely populated areas in the world.

Ms Rein braved pouring rain caused by the approaching Cyclone Phyan to take books and educational toys to the 24 children at the kindergarten, known locally as Muskaan, which means smile in Hindi.

She was greeted by a young child with a bunch of flowers before the youngsters sang and danced for Ms Rein.

Before long, Ms Rein was taking part in the routines performed by the infectiously joyous children, who are receiving an education not offered to many of their contemporaries.

The children then gathered together to hear a story First the Egg by Laura Vaccaro Seeger read by Ms Rein as she perched on a tiny stool in the concrete room decorated with posters and toys.

Their kindergarten is run by the non-government organisation Reality Cares, an offshoot of Reality Tours and Travel, which has been running tours of the slum for a number of years.

One of Reality Cares' co-founders, Chris Way, said the kindergarten was started in July this year and the organisation was looking to expand the facility as it receives more funding. The Australian high commission is considering a direct aid grant of up to $30,000 for the Muskaan kindergarten, which would be used to fund the training of teachers.

Mr Way said the organisation was in discussion with the local government-run primary school about taking over one of their classes so the children could continue with the special program.

Ms Rein is in Mumbai as part of a visit to India by Mr Rudd.

AAP