Image caption The widows of Vrindavan - they are often cast out by their families who don't want to pay for them

The rape and murder of a student on a Delhi bus in 2012 made headlines and sparked protests about violence against women. But there are other hazards for women in India, and particularly for single women - who are often unable to live a normal life.

Wearing a long, bright yellow frock and two well-oiled plaits, she was silently doing her chores in a village home when I first saw her.

For a moment I took Khuddo to be a teenage domestic help, a small girl cooking, cleaning and mopping, just like millions of them who work in homes in India's teeming cities and villages.

But when she turned and flashed a shy smile, I saw a face of an older woman. And then I discovered, to a creeping sense of shame, that she was not a domestic help either.

Khuddo lived with a vast, extended family in a crowded home with her widowed mother, aunts, uncles and their families. She had four siblings who lived and worked all over India. Her father had passed away a long time ago.

Khuddo was about 50, and single. Even as the family grew, she had faded into the background, immersing herself in the drudgery of dull and backbreaking chores. She contributed nothing to the thrumming noise of the family. They called her their "tragic case". "Sometimes, it feels," a family member told me, "she does not exist at all."

Why do you dress like a girl, I asked her. Her mother answered instead.

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"She is unmarried, so she should not look or dress up like a woman."

The family refuses to accept that a woman can be grown-up and still not be married. So to them Khuddo is still a child. [or "a child woman"?]

Khuddo is one of many Indian women who have simply sunk into oblivion because they remained single, not by choice, but by circumstance or a twist of fate.

In a society where a woman is traditionally considered to be complete when she marries - preferably to a groom of her parents' choice - singledom can be cruel and oppressive.

There are some 40 million women in India, according to the 2001 census, who are single and over the age of 30 - divorced, separated or unmarried. This is believed to be a conservative estimate.

Many of them are beginning to defy convention by remaining single by choice, and eking out a life for themselves without depending, like Khuddo, on the grudging munificence of their families. India's fast-changing cities are also slowly beginning to accept single women for what they are. But the change is extremely slow and painful for many who are facing it every day.

Image caption Deepali fears the social stigma of divorce

If being single can sometimes relegate a woman to the background, divorce can be traumatic. Social stigma surrounding divorce still hangs heavy over women, usually housewives, who are dependent on their husbands.

That's not all. If a married couple splits up, the woman generally struggles to receive her fair share of the couple's property. And even what she is entitled to can get tied up in litigation in India's excruciatingly slow-moving courts.

Deepali, 25, from the city of Mumbai, is a sorry example of how a slow justice system and social stigma can unwittingly conspire against a separated woman, especially with children.

She lives in a grotty one-room tenement with her four-year-old son, and does odd jobs as a waitress at wedding parties or as a housemaid.

Her husband abandoned her and initiated divorce proceedings after his family rejected her.

She says she has received no maintenance payments in the three years they have been living separately. It says a lot about Indian society that she is keen to be reunited with her husband, despite the fact that he used to beat her regularly.

Find out more The BBC's Rupa Jha talks to four single women living in India

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"I don't want a divorce. My son and I need the name of the father to avoid social stigma. Society should not say that my son is illegitimate," Deepali says.

"I don't want to be called a divorcee. So I'd rather carry on like this. I also think what my son will think of me when he grows up if I end up being a divorcee! Good women don't end up as divorcees, you know."

Nimisha, in her 30s and working, does not fit the description of a "good woman" by that logic. She is among a very small but growing number of women who are walking out of abusive marriages despite the social and financial costs.

Her decision to seek a divorce from her husband was a blow to the prestige of both families, but now, she says, people have started accepting her and her new status.

"It's a hard life to be single and divorcee in India but I would rather be single than be in an abusive marriage," she says.

Image caption Widow Shakti Dasi was beaten up by her sons

Shakti Dasi is another kind of single woman - a widow aged 65. I met her in Vrindavan, a holy city where large numbers of Indian widows take refuge if life with their family becomes unbearable.

"When my husband was alive, I had his protection," she says, tears welling up in her eyes and her voice choking.

"Then he died and I was like an orphan. My sons and daughters-in-law no longer cared about me. I was abused and beaten up by them. Once my son broke my legs and I decided, I didn't want to live with my family any more."

Like many of the widows in Vrindavan, who are mostly from poor, rural backgrounds, she had little to lose by leaving home. The life she'd taken decades to create had already been taken from her.

Now she lives in a small brick shack, impoverished and alone.

Image caption Shakti's small brick shack in Vrindavan

The reasons for tensions between widows and their families are primarily economic, says Winnie Singh, a social activist who works with the women of Vrindavan. A widow is an extra mouth to fill and could try to stake a claim to the family property.

Winnie tells me the fact that these widows don't resist is deeply rooted in their culture.

"They still hope when they die, that their son probably will come and light their pyre," she says. "A son who breaks your legs, a son who hits you so hard that your skull breaks, a son who is willing to put cow dung in your mouth - and yet you want the same son to come and light your pyre. We need to break that mind-set also, somewhere."

Image caption Activist Winnie Singh says mind-sets need to be changed

Living as young, unmarried adult woman in a women's hostel in the Indian capital in the late 1990s, I realised how, in the name of protection, women are sometimes excessively fenced off. You had to be back in your room by seven in the evening, you could not leave the hostel before six in the morning, you could not invite male friends, and you had a quota of nights out with the consent of a "local guardian".

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Those of my women friends who were single and lived alone faced similar problems. Getting a place to live in was tough, there was the unrelenting gaze of the landlord and neighbours to contend with, and male friends visiting them were a no-no.

Things are changing but the process is glacial. India is a complex society that reveres goddesses and yet seems to discriminate against living women in equal measure.

Interviewing Indian women over the last few months has been an uncomfortable experience.

If you are single, you could just fade away. If you are separated or divorced, you may struggle all your life - so many women stay in a bad marriage and suffer. And in some families the prospect of being widowed does not bear thinking about.

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