An Israeli woman received an unthinkably tragic update on the fate of her daughter, who has autism, and her elderly mother 12 days after they were taken by Hamas: their bodies were found at the Gaza border, authorities told the family.

Galit Dan's daughter Noya, 12, and her mother Carmela, 80, were taken from their homes during the Hamas attacks on their Kibbutz, Nir Oz, on Oct. 7. Dan said three other members of their family are still missing: her niece Sarah, 16, nephew Erez, 12, and brother-in-law Ofer, 52.

Dan's sister, Hadas Kalderon, the mother of Sarah and Erez, told ABC News, "I have no time to grieve, I need to save my children's lives."

"Two days ago, we celebrated my mom's 80th birthday without her," Kalderon said. "We had a lot of hope. Yesterday, we received a message that she and my niece Noya had been murdered. We believe they were murdered outside of Israel, in Gaza, but we don't know the exact details."

"Now, I am supposed to sit for seven days and grieve for them, but I don't have the time because I have to fight to save my children's lives and all the other children and elderly who are still alive," Kalderon said.

"Our kibbutz experienced a horrific pogrom," Kalderon said Thursday, 12 days after the attack. "They burned most of the houses. We don't have a home to go back to, but I don't care about the home, I care for one thing - we have to release the children and the elderly immediately."

In a post on social media, Carmela's niece, Noam Dan, said, "We are in great pain … we have three more souls to save in our family."

In an interview with ABC News a week ago, Galit Dan said at the time she was holding on to the hope that Noya, who needs around-the-clock care, is being looked after by mothers in Gaza.

"The only thing I want and choose to imagine is that there are Arab women around her," Dan said as she sat diligently beside her laptop and a big pile of notes, visibly worn out by her tireless mission to get Noya back into her arms.

"You don't see women in the pictures from Gaza Strip. I just hope they are with my daughter and with my mom and they are taking care of them," she said last week. "I hope they are being human. Because the people who came into the Kibbutz, there were not human."

Noya was on a sleepover at her grandmother's house at the time, five miles from her mother and sister who were taking cover in their safe room when Hamas stormed their street, her family said.

Dan herself was holed up in their house for more than 10 hours with her other daughter Tamar during the attack by Hamas: "I told her not to breath, not to move, I was sure we were going to die."

She said a terrified-sounding Noya sent a voice message on the day of Hamas' attack: 'Mummy, I'm scared. There are people in the house - help me.'

That was the last message Galit said she ever received from her daughter Noya.

The other message was from Kalderon: "Galit. Holocaust."

"We are all kids of Allah, of Jesus, of God, we are all kids and we are all parents and sisters and sons of somebody," Dan said in a message to Hamas last week. "Be connected to your heart, be connected to humanity."