"Ever since October 7, it's been a living hell. We want our kids back safe and sound as soon as possible."
Hamas fighters murdered Kalderon's mother and niece, and on the same day kidnapped two of her children, daughter Sahar, 16, and son Erez, now 12, along with their father Ofer.
The trio are believed to be among 240 hostages taken during the surprise raid in southern Israel.
As Israel steps up retaliatory military attacks in Gaza, ordinary citizens like Kalderon are caught in the middle.
"I'm just a mother. I'm not a soldier or a politician," she tells NHK World.
Hiding in a safe room
Kalderon was a resident of Nir Oz, a kibbutz that was one of several communities attacked by the Islamic group Hamas. She was at home when she realized that something was wrong, prompting her to hide in a safe room.
"On October 7, at 6:30 in the morning, I woke up and I heard a massive explosion. We are used to bombings, but this time, something was different. I went into my safe room.
"I could hear the shooting outside. There were loud noises, things breaking, people screaming and speaking Arabic."
The last contact from her family
As Kalderon struggled to understand what was happening, a message appeared on her phone: Hamas fighters had entered the kibbutz.
She received a picture that showed her mother, who also lived in the kibbutz, was lying in a pool of blood.
Kalderon's thoughts turned to her children, Sahar and Erez, and their father, Ofer, who were at another house.
Kalderon tried to call them. Hamas fighters had entered the house where the three were staying. Ofer, Sahar and Erez escaped via a window and were trying to hide in bushes.
"Mom, please be quiet. I love you," said Erez. Then Kalderon heard Sahar call out, "Mom, Mom, Mom..." and with that, Kalderon's cell phone battery ran out. That was their last communication.
Preparing to die
Kalderon was also in grave danger. The militants were banging on the door and walls of her safe room. She says she was preparing to die.
After more than eight hours in her safe room, the Israeli army arrived at the kibbutz and Kalderon made her way out.
Under the direction of the soldiers, the community searched for survivors.
Everyone was directed to gather in one place, but none of Kalderon's family members appeared. She begged a soldier to search the bushes where her two children and their father had been hiding.
Later, an acquaintance got in touch to let her know about a video on social media that showed Erez being kidnapped by the militants.
The Israeli government then officially informed her that the three had been taken as hostages, and that Kalderon's mother and niece were dead.
"From that time, I'm in a living nightmare," says Kalderon. "I can't even sit down to feel the pain. I am just fighting to bring back my children and their father. I have no information and I don't know if they're still alive, if they eat, or what their conditions are like."
A missed birthday
October 26 was Erez's 12th birthday. Kalderon bought a cake to celebrate what should have been his day.
"But he wasn't there," she says. "He celebrated his birthday in captivity in Gaza, without us. I can't say even 'celebrate' because I don't even know what words to use."
'Hamas murdered our souls'
On October 30, Kalderon returned to a badly damaged Nir Oz for the first time since the attack.
The kibbutz was once described as a beautiful, nature-filled village. But there is no trace of that now, just fresh marks of the horror that unfolded there, and an unnatural stillness.
The house where Kalderon's children lived is largely a charred ruin.
When she visited her slain mother's home, Kalderon found that many of her mother's most prized possessions were missing, presumably looted by the militants.
"I said to my mom, 'Sorry that I wasn't there to help you,'" she says. "We used to sit down together for Friday meals, to laugh, to tell stories. But that's all gone now. I feel like Hamas murdered our souls. We don't have a home to go back to. We are refugees in our own country."
As for her children, "I miss them so much. I want to feel them and hug them. I'm afraid because I don't know what's going on. I just want them to come back immediately."
Kalderon says it's unfair for ordinary people to be suffering like this. "How can we have citizens, children, and babies, as victims of war?"
