She spent 14 years caring for a granddaughter with cerebral palsy. Then she shot her, police say.

Before the shooting, Julia Cash-Owens - with her degree in juvenile justice and decades in social work - appeared well-equipped to protect her vulnerable grandchildren from the chaos that family members said loomed at the edges of their lives.

Both of her daughter's children had special needs. Julian Castillo has autism, family members said, struggled with potty training, and would throw fits if asked to eat anything other than string cheese or pop tarts.

Aurelia Castillo, 14, who was diagnosed with cerebral palsy at birth and couldn't speak, used a wheelchair to get around and needed a service dog to alert family members of oncoming seizures.

Still, Cash-Owens was a 58-year-old doting grandmother, a fact that anyone who followed her on Facebook could see.

In photos snapped last fall, Aurelia, who everyone called Rae, sits in front of a field, a pumpkin on her lap. In another, she's at a petting zoo, a camel photo-bombing the picture.

The grandmother was dead when police officers arrived at the house. The granddaughter she'd spent 14 years raising died at a nearby hospital.

Police say the investigation is ongoing - an autopsy was conducted Tuesday - and they have not released a motive in the shooting.

But family members said they'd worried for years about a grandmother who was trying to balance too much.

The children's mother had a litany of personal problems, a family member told The Washington Post. Now Cash-Owens, who served as nurse and primary caretaker and, at times, the only one who could get Julian to eat, was accused of killing her granddaughter.

"She was exhausted," her daughter-in-law, Chanda Fowler, told The Washington Post. "She was doing so much, and it's just unfair for her to be characterized as a murderer."

The children's mother, who confirmed the deaths to local news stations, did not return calls or messages seeking comment from The Washington Post.

Chanda Fowler, who is married to Cash-Owens's son, Adam Fowler, said she and other family members had worried that the children were being raised in a troubled home. Those accusations could not be immediately corroborated Wednesday.

At one point, Cash-Owens had moved to San Antonio with her daughter. It was partly to be close to her grandchildren, Chanda Fowler told The Post, and an effort to bring some stability to their lives.

But about a year ago, Chanda Fowler said, she got a call at work. Things weren't working out in Texas. Cash-Owens, her daughter and the children were coming back.

They crammed into the Fowlers' house on a lake outside Shelbyville for a bit, then got a one-story house on Hunting Hills Drive.

But that proximity made two things clear, Chanda Fowler said: Cash-Owens's role in her grandchildren's life was outsized, and it was having a negative effect on the older woman.

If there was a problem, she kept it to herself, Fowler said. On Facebook and with family, she'd stay upbeat, focused on the progress and achievements of "my babies."

There was the photo she posted of Julian, in a button-up shirt during an event at school. She'd made that photo her profile picture, and included a frame from the Autism Speaks advocacy organization: "Different Not Less."

And there was a photo of a younger Rae in 2011 in which Cash-Owens wrote: "I knew I loved my children, but my grandchildren are fabulous."

Fowler said she and her husband cautioned Cash-Owens to take a step back, if only for a little bit.

"It's like being able to turn your phone off. Or it's getting to take a one-hour nap," Chanda Fowler said. "We begged her to bring the children here, but it was very hard. Even when that would happen, she couldn't relax because she was so scared that something was going to happen."

Caregiver burnout is not uncommon, especially in older adults, according to AARP.

"This may be the hardest job you'll ever have, and it can take time to adjust and come to terms with it," an AARP article on caregiver burnout said. "No one functions well in crisis mode day after day. Caregiving is a marathon, not a sprint. You need to find a way to dial down the tension."

In a message to family and friends on Facebook, Adam Fowler said taking care of people had been a large part of who his mother was since he could remember.

"My mother spent her entire life helping underprivileged children," he said. "She retired and took care of her mother and grandchildren. She spent everyday caring for my niece, Aurelia, who had severe Cerebral Palsy. She also was raising my nephew, w/special needs. This is also the same woman who went to bed hungry when I was younger so her kids could eat. I'm so heartbroken that this has occurred."

She often did it without complaint, family members said, although her burden would sometimes seep out on Facebook - like in July 2011, when the seizure service dog arrived.

"She is only 8 weeks old, but very smart," Cash-Owens wrote to her followers. "I slept on the couch with her last night. not sure this is how it is supposed to be. miss you folks bunches and bunches. but I am where I am supposed to be, with my babies."

And about a year ago, after Cash-Owens's mother died, she wrote a singular emotional comment in a sea of upbeat updates about grandchildren.

"How are you?" she wrote in response to a friend's post. "My mother has been gone 7 months now and I still can not believe it. Feel pretty alone. Do you?"