Nicole sleeps next to her aunt Siomara, who has been raising her since her mother was murdered. At 6 years old, Nicole suffered from night terrors and didn’t like to sleep alone.

Six years ago, Greta Rico’s cousin Fernanda was found dead in a garbage bag on a street in Mexico.

She had been shot three times, and there were signs of sexual violence.

As her family waited for more answers — answers they ultimately never got — there was an especially pressing issue: Who would take care of Fernanda’s 3-year-old daughter, Nicole?

Nicole’s father was absent. Her maternal grandmother had died five years earlier.

In stepped her aunt Siomara, a single woman who, at 27 years old, never expected to be a mother.

“She never ever wanted to be a mom, and she actually was very emphatic about this,” said Rico, a photojournalist who has been documenting Siomara’s story in a project she calls Substitute Mother. “And then because of what happened, when she decided to take care of Nicole, it was super, super hard for her. I would dare to say that it is still hard. But they love each other so much and they already have a natural dynamic of mother and daughter.”

Rico’s photos illustrate what life has been like for Siomara and Nicole over the past few years, from the highs to the lows, and she wants to raise awareness about femicide, the most extreme form of gender-based violence that is defined as the “intentional murder of women because they are women.”

Most countries, including the United States, do not distinguish femicides from other homicides. Mexico is one of at least 16 countries that do. But women’s rights groups in the country have said that too few murders are classified as femicides and not enough perpetrators are brought to justice.

Fernanda’s death was never investigated, Rico said, and it wasn’t classified as a femicide even though there was evidence of sexual violence.

“A lot of women here in my country, for a few years now, we are feeling that the authorities just don’t care about our lives, just don’t care about what happens to us,” Rico said.

She would like to see her government do more to help the orphans of femicide and their caregivers, who she says are almost always women in her country: the sisters, the aunts, the grandmothers.

“There are no public policies to support these women,” Rico said. “There is not even a legal term to call these caregivers. And there is no kind of aid for those children.”

Since Fernanda died, Siomara and Nicole have moved nine times. Rico said it hasn’t been easy for Siomara to keep a job that allows her the flexibility she needs to take care of Nicole.

“She’s a girl that has trauma, that needs a lot of care, that needs a lot of psychological support,” Rico said. “And this has been difficult for my cousin because very often, she needs to ask permission from her job maybe to change the schedule or maybe to not go in every once in a while. What always ends up happening is that she gets fired. She has changed jobs a lot since everything started.”

Siomara now works in sales at a mall, and she’s been able to keep the job for a year, which is the longest she has managed to stay employed since her sister’s death.

What has been a big help is Nicole’s recent enrollment in a special boarding school that was created for girls who come from vulnerable situations. She lives there five days a week now, getting the education and psychological support she needs. It has also given her more stability.

“She’s not moving from school again and again, and she’s not changing friends again and again,” Rico said. “Now she has a lot of good friends. They actually will sleep together in the same room. They already have a routine. They care about each other a lot; between them there is also a strong bond. They are like family.”

Siomara will pick Nicole up on Fridays, and they will spend weekends together, as well as holidays and vacations.

“Sometimes I don’t want her to stay in the school, but I’m alone with this and it’s the only way I can keep working,” she said.

Before her sister died, Siomara had plans to continue her studies, maybe travel abroad. Those plans were put on hold.

Being a mom has been a struggle sometimes, she told her cousin.

“There are days when I feel like I can’t,” Siomara said. “It hurts me a lot to have my dreams (set) aside. But when I think of (Nicole), I realize that she needs me.”

Siomara and Nicole were close before Fernanda’s death. When Siomara was younger, she was the “cool auntie,” taking Nicole to the movies and spoiling her with toys.

Now they are not only like mother and daughter, Rico said, but they are also best friends.

“It has been very, very beautiful to be around them, seeing them getting stronger together,” she said. “One of the things that has been interesting for me is that I’ve seen that they created a very strong relationship of confidence. There is no way at all that something will happen to Nicole and she won’t tell my cousin. She tells her everything all the time.”

In her photo project, Rico wants to show the hard situations that the two have been through, but also the moments of joy. She says Nicole, who is now 9, is a fun girl who is smart.

“If you ask her, ‘What do you want to be when you grow up?’ she will answer, ‘I want to be an astronaut,’ ” Rico said. “She’s now obsessed with space. We bought her like a cardboard spaceship last Christmas and she’s obsessed with playing with her spaceship.

They’ve encouraged Nicole to follow her heart, wherever it may lead. Her love of dinosaurs recently made Rico and Siomara realize how problematic gender roles can be in their country.

“Just so you can get an idea of what Mexican society is, you can only find dinosaur things, like clothing or toys, in the boys section,” Rico said. “You will never ever see a pink pajama of dinosaurs in the girls section. This is not an option in here. If we take her shopping, we just tell her choose whatever you want. It doesn’t matter the section where you choose it.”

Nicole knows her mother died, but not that she was killed. Rico said they will have that conversation in time, and they are working with experts at her school to find the best way to do that.

“The reality is that she does know that something happened, because everything was very weird and very fast, and a lot of things happened and were said, especially in the moment of the funeral,” Rico said.

Within months of the funeral, Nicole started calling Siomara “mom” — and she still does today. Siomara never told her to call her that; it just happened.

But Siomara wants to make it clear that Fernanda — and the circumstances around her tragic death — are never forgotten.

“I want people to know that although I love her very much and I will always take care of her, I am not her mother,” Siomara said. “I am her aunt, and I had to become her mother because they killed my sister.”

Rico said that too often in her country, people romanticize the sacrifices these caregivers make and forget about trying to fix the femicide problem or help the caregivers to manage the fallout.

“A lot of people think that because these children are with someone who actually loves them and cares for them, that will be the solution,” she said. “And the reality is that it is super difficult. Even though my cousin loves Nicole very much and was very supportive of her, she didn’t have the necessary tools to help a little girl with trauma. She didn’t have the tools to face the brutal situation that someone killed her sister — and also to face her own pain.”

Rico says more is needed — from the government and the community — to help women like Siomara.

“The reality is that they’re doing this job and they are facing these situations alone,” she said.