Jessica Whitford is searching for answers after Manitoba RCMP ruled her sister's death a homicide.
Lydia Whitford had autism, epilepsy and was non-verbal but was full of love and life, Jessica said.
"How could somebody hurt someone like her? She wouldn't hurt anybody. She was innocent," Jessica said.
On July 14, RCMP were called to a residence in the Rural Municipality of Springfield where they found 18-year-old Lydia dead.
On Tuesday, RCMP said the young woman's death was a homicide and the Major Crimes Unit and Serious Crime Unit are investigating.
Jessica, 19, said she was very close with her sister growing up. They were close in age and spent a lot of time together when they lived on Sandy Bay First Nation and later in Portage la Prairie.
"She didn't speak [but], me and her, growing up, had our own way of talking to each other. We had our own language. I understood her. I did everything with her to make her feel not different," Jessica said.
When the sisters were aged 10 and nine there were some family issues and the sisters ended up in care, Jessica said. Over the years, Jessica, who is no longer in care, said she tried to keep in contact with her sister but she says she ran into roadblocks with Sandy Bay Child and Family Services.
In July, Jessica said the agency told the family her death could have been from natural causes, her medication or a seizure. However, Jessica wasn't shocked to find out it was ruled a homicide because she says there were bruises along Lydia's arms and collarbone when she went in to see the body.
"Learning that today, that really hurt me but I wasn't surprised because of the bruises," Jessica said.
Jessica doesn't have a lot of information about the residence in Springfield but said Lydia usually didn't go places without supervision.
"Why would somebody hurt her and take her life from her?" Jessica asked.
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The death has been difficult on the family and Jessica started to self-harm, but she stopped because her "sister would want better" for her. Now, she is calling for answers around what happened to her younger sister, particularly because Jessica says Lydia was still in CFS care.
"I'm doing my best to stay strong for [my mom] and my sister and if my mom can't be the voice then I will," Jessica said.
CBC has reached out to Sandy Bay Child and Family Services and the province for comment.
The rural municipality is located just east of Winnipeg.