A 16-year-old girl has been charged in the shooting death of her 12-year-old sister.

This afternoon, their 33-year-old mother, Connie Moreno, stared at the last family photo of her girls during an outing to Kemah Boardwalk last month.

On Sunday, Galveston police believe 12-year-old Juanita Martin was accidentally shot and killed by her older sister, Annie.

The teen has been charged with aggravated assault with a deadly weapon. She is currently being held at the Galveston County Juvenile Detention Center in Texas City.

"It was an accident, the shooting, and they make it seem like my daughter intentionally shot her sister and that's not true," said Connie Moreno.

Galveston police believe the sisters along with a third sister were playing with their mother's gun when it went off.

Willie Jones Jr. lives across the street from the home on the 3500 block of Avenue N 1/2. He was the first inside after Juanita's 15-year-old sister ran to get help. Jones said he found Annie holding Juanita while begging her to hold on.

"That was a freak accident and the best thing that can come out of this is to get her sister some therapy," said Jones.

The 12-year-old was airlifted to Memorial Hermann Hospital were she later died. Her sister was taken into custody.

"I know and God knows what we are going through," said Moreno.

Outside Moreno's home is a growing memorial of teddy bears and flowers in memory of her youngest child.

Family friend, Denzel Lee, told 39News it was inside the home that he first saw the gun in question.

"It just popped upÂ… when I was in the house, they pulled it out the box because a situation was going on," said Lee.

Lee said the girls' mother kept the gun as protection for her family. Moreno was not home at the time of the shooting even so she is facing possible charges.

"We're still investigating the shooting and there are some charges that may be filed against the mother for making a fire arm available to a minor," said Lt. D.J. Alvarez, with the Galveston Police Department.

Despite that possibility, Moreno is too busy preparing to say a final good bye to her youngest daughter. She has also hired an attorney to help her get her oldest out of juvenile detention.

"I just want to tell my daughter that I love her and I am going to bring her home - not to worry about it," said Moreno.