Renu Sharma,24, and her husband Jainarayan , who live in Delhi, already have two children - Lakshya, five and Divya, three.
The whole family went to the National Zoological Park in Delhi to celebrate Monica's birthday.
'I'm watching her grow into a healthy, happy girl'
Renu told the WHO: "She is a picture of health. She has a good appetite and I am still breastfeeding her about 10 times a day.
"She already eats porridge, lentil soup and she loves wheat rotis or chapattis.
"Her birthday cake was also a real hit."
She added: "Two weeks before her birthday, Monica started walking by herself. She is quite wobbly but can already take a few steps without any help.
"She can also crawl upstairs quickly - which means she is becoming quite a handful and difficult to mind when I am busy doing household chores.
"Monica is also making all the usual baby noises. Her favourite words are baba and mama."
Renu added: "We have decided not to have any more children. I was sterilised after giving birth to Monica."
The WHO warns 62 of every 1,000 children die before their first birthday in India.
Nine months old
"I don't know how much Monica weighs because we don't have any scales - but when I carry her I can tell you she's getting heavier!
'I bathe Monica every morning'
"But, apart from a couple of minor colds in the last few months, she seems quite healthy.
"Monica is sitting up and crawling quite happily. She has also started to stand up, but is still very wobbly on her feet!
"She's also started to say a few words like 'mama' and 'baba'."
Renu said her husband spends time with Monica whenever he can, despite his long working hours.
"He's really enjoying being a father for the third time," she told the WHO.
Renu added: "I'm feeling OK, although I'm still tired.
"My husband thinks I'm losing weight though. I don't eat much during the day - just a small amount for breakfast, then some dinner."
Renu and her family have access to clean running water through a pump in her garden and via local authority supplies.
She added: "We live in a malaria-affected area, but luckily at the moment there aren't many mosquitoes around.
"Monica and her brother don't sleep under a bed net."
In India, even in areas where bed net programmes have been introduced, only 38% of under-fives sleep under nets.
At six months
"It's wonderful to have another baby in the family.
"Monica is a happy child and very active.
"She is also thriving and now weighs 6kg and is 67cm tall. I feel fine too - just very tired.
"Monica has started crawling around at high speed. It's exhausting keeping up with her!
"I sleep around six hours each night and work for 18 hours each day.
"I'm back to doing my household chores - both at my family's home and at my in-laws"
In India, 38% of infants between six and 11 months old are underweight.
Six-month-old girls should generally weigh between 5.8 and 9.2 kg, while boys of the same age should usually be between 6.4 and 9.7 kg.
Renu added: "I am still breastfeeding and Monica has just begun to show an interest in solid food.
"At our last check-up I was advised to start giving her food like mashed bananas, porridge, lentils and rice.
Six weeks old
Renu told the WHO: "I feel very well - rested and happy. My only responsibility at the moment is looking after Monica. I'm breastfeeding her around 10 times a day.
Renu was told to eat healthily after her daughter's birth
"We're spending a lot of time together as a family, and Monica's brother and sister love playing with her."
Renu has just taken her baby for her second round of vaccinations at a nearby clinic. On the day she attended, there were at least 300 other babies there receiving polio vaccines.
In India, one in 12 children die before the age of five, the majority from preventable and treatable disease such as malaria, pneumonia and measles.
Seven days old
"I have been resting at home.
"Following Hindu custom, I am in confinement for 38 days at my parents-in-law's home, then I'll rest for another 38 days at my parents' home.
"After that point, I'll be expected to return to work in the fields."
She added: "The doctors have advised me to eat extra-nutritious foods such as leafy green vegetables, cereals, lots of extra milk, and proteins.
"I'm eating a lot of 'halwa' - wheat flour roasted with butter, and 'khichidi' - boiled rice and lentils."
"I had an appointment at the hospital to be induced, because I was more than two weeks overdue.
Renu with her new daughter
"The hospital was very busy. The day I gave birth, there were 25 women waiting to deliver, and only nine beds in the pre-natal ward."
Seven months pregnant
"In India, it is illegal to determine the sex of a baby before it is born, so I don't know whether I am having a boy or a girl.
"However, my preference would be to have a little boy."
Renu said all her family have been supportive.
She has been to two ante-natal check-ups where she was told she was anaemic and was given iron and calcium tablets free of charge.
Five months pregnant
"Despite being five months pregnant, my days are long and busy," Renu said.
"I help with the household chores, work in the fields, and look after the family's cows.
Renu said she had had no ante-natal check-ups during her pregnancy.
In 2000, India had the highest number of deaths in childbirth of any country in the world.
South Asian countries have the lowest levels of antenatal care anywhere in the world. Almost half of pregnant women have no check-ups.
In India, just 42.5% of births are assisted by a skilled attendant. The WHO says all women should have access to skilled professional care during childbirth to ensure the baby is delivered safely.
Where the women live
Photos courtesy of the World Health Organization.