Bipolar girl aged just 11 is feared to have formed SUICIDE PACT with brother, 31, who shot her dead before taking his own life behind wheel of his Mustang

The mother of a bipolar 11-year-old fears she may have made a suicide pact with her adult brother, who killed the boy before shooting himself.

Lilea “Lilly” Stolworthy, 11, was shot outside her home in Medical Lake, Washington, on Sunday with a gunshot wound to the head. Her brother Jordan Brownlow, 31, is suspected of killing her before turning the gun on himself.

Both had both attempted suicide several times in recent years, with the children's mother, Darel Stolworthy, raising fears that they had agreed to die together. Brownlow sent a final text to the family group chat that read: “I'm sorry, please forgive me.”

Researchers have yet to comment further on the suicide pact theory.

The troubled siblings were among 12 shared by Darel and her husband, four of whom were adopted, including Lilly.

Darel Stolworthy, who counts the siblings among the 12 children she shares with her husband, four of whom are adopted, including Lilly, revealed that they had both struggled with mental health issues in recent years before the tragedy.

Lilly had run away from home shortly before Thanksgiving and her family decided to give some of her belongings to Brownlow for temporary storage, according to a local outlet. The spokesperson's comments.

The child then returned home wanting the items back, and went with Brownlow to his car to retrieve them.

According to the Spokane County Sheriff's Office, she was approached by her brother before witnesses heard gunshots followed by a Ford Mustang fleeing the scene.

Brownlow was found slumped in his car about 20 minutes later with a gun in his hand, and remained on life support for several days before being pronounced dead Wednesday. His organs have been donated.

When Lilly didn't return with her brother, Stolworthy went looking for the duo before making the nightmarish discovery that her adoptive daughter had been shot in the street outside their home.

Despite her young age, Lilly had attempted suicide several times, and her mother said in their last conversation that the child told her she wanted to be “done” with life.

The haunting last message Brownlow sent to his family before the tragedy read in an affidavit: “I'm sorry. Forgive me please'

The child was shot and rushed to hospital on Sunday but was tragically pronounced dead after succumbing to her injuries.

Lilly and her brother were last seen together on Thanksgiving before he allegedly shot her on the street in front of their home before driving away and shooting himself nearby

Lilly was rushed to hospital but succumbed to her injuries, and her grieving mother now says her daughter's ongoing battle with mental health may have led to the tragedy.

She said KHQ that her 11-year-old daughter had made a number of suicide attempts despite her young age and that she had been diagnosed with bipolar disorder.

Although Lilly was on medication, her recovery was hampered by a lack of guidance due to a shortage of suitable facilities and the child's unwillingness to submit to therapy.

In a heartbreaking confession, Stolworthy said that in her last conversation with her daughter, Lilly also said she wanted to be “done” with life.

She insisted that while her son's alleged murder was a terrible thing, she believes Brownlow saw his actions as a way to protect their family.

Although there are fears that the siblings planned to commit the murder-suicide in advance, no direct evidence has been released by authorities to support this.

The Spokane County Sheriff's Office did not immediately respond to a request for comment when contacted by DailyMail.com.

At a vigil for Lilly held Thursday, Lilly's mother urged attendees to “get help if you need it.”

An attendee at the vigil described Lilly as “so kind” and “always so polite,” and said the other kids in the neighborhood “loved her.”

A vigil for the 11-year-old was held in Medical Lake on Thursday evening, where nearly 100 people braved the freezing temperatures to pay tribute to the child.

Stolworthy addressed the crowd at the solemn event, thanking them for their support of her family and saying the turnout showed the impact her daughter had at such a young age.

“Looking around at all these faces that were part of Lilly's life makes me happy,” she said.

“Get help if you need it,” Stolworthy told the crowd. “She would want you to be happy and healthy. Use her as an example to get help when you need it. Be kind to each other.'

Natasha Hargrave said her daughter and Lilly had been “best friends since kindergarten” and was “just like any other child” despite her arguments.

A great-grandmother, Patty Herker, said her relatives lived down the street from Lilly and “the kids talked about her all the time.”

“She was just so nice,” she added at the wake.

'I've never had any problems. She was always so polite. The kids loved her…We will miss her very much.”

If you or someone you know needs help, you can reach Samaritans NYC at 212-673-3000 or the Trevor Lifeline at 1-866-488-7386.

For confidential help, call the National Suicide Prevention Lifeline on 988 or click here.