(CNN) She will be remembered as the would-be bomber whose device failed to detonate in a string of otherwise deadly terror attacks at Jordanian hotels in 2005.

Sajida al-Rishawi was sentenced to death for that attempt, and Jordan executed her early Wednesday.

But just who was she? And what's her connection to the new radical Sunni group that controls big swaths of Syria and Iraq?

Al-Rishawi was referred to as an "imprisoned sister" of the terrorist group in a message purportedly posted online by a known ISIS supporter.

The message proposed a swap of al-Rishawi for Japanese hostage Kenji Goto . In the video, Goto was seen holding a photo of what appeared to be beheaded compatriot Haruna Yukawa.

The online posts, which CNN could not verify independently, appeared four days after an ISIS video demanded that the Japanese government pay $200 million within 72 hours for the hostages' release

In the latest recording, the voice of a person claiming to be Goto was heard in English blaming Japanese Prime Minister Shinzo Abe for Yukawa's death. Forgoing the money, the voice then issued a new ISIS demand: the release of al-Rishawi.

"They are just demanding the release of their imprisoned sister Sajida al-Rishawi," the voice said.

Out of sight for almost a decade

Al-Rishawi, who was being held by authorities in Jordan, was not seen publicly in nine years.

Sajida al-Rishawi is seen in a frame from Jordanian television in 2005 where she confessed her participation in the deadly attacks at Amman hotels.

In a televised confession in November 2005, al-Rishawi calmly recounted how she tried to take part in a string of terror attacks at Jordanian hotels that month that killed at least 57 people.

"My husband detonated his bomb, and I tried to detonate mine but failed," al-Rishawi said on Jordanian television, showing no emotion. "People fled running, and I left running with them."

In 2006, al-Rishawi was sentenced to death, but that same year, Jordan imposed a moratorium on the death penalty. Executions resumed last month.

Wearing a white head scarf and black dress during the confession, al-Rishawi displayed a belt rigged with explosives and crudely held together with tape.

Jordanian authorities said al-Rishawi, now in her 40s, joined her husband, Hussein Ali al-Shamari, to carry out the suicide bombings at the Radisson hotel.

His explosives went off, killing 38 people attending a wedding reception in the ballroom. Three male bombers and 57 bystanders were killed at three hotels in the series of attacks.

She said she was an Iraqi who lived in Ramadi and, using fake passports, traveled to Jordan with her husband. She told Jordanian authorities that her husband taught her how to use her explosives belt.

In the confession, al-Rishawi said, "My husband is the one who organized everything."

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Jordan: Al Qaeda was behind attacks

Jordanian authorities at the time said the attacks were orchestrated by the terrorist group al Qaeda in Iraq, which was led by Jordanian-born Abu Musab al-Zarqawi.

Al-Zarqawi was killed in a U.S. strike in June 2006. A post on a website used by al Qaeda in Iraq claimed responsibility for the Jordan attacks.

Deputy Prime Minister Marwan Muasher said after the attacks that al-Rishawi was the sister of Zarqawi's "right-hand man," who was killed in Falluja, Iraq. He did not identify the lieutenant.

This image from video posted on a militant website on July 5 purports to show ISIS leader Abu Bakr al-Baghdadi delivering a sermon at a mosque in Iraq.

ISIS leader Abu Bakr al-Baghdadi was a lieutenant of al-Zarqawi, retired Lt. Col. James Reese, a former U.S. Delta Force commander, told CNN.

"There's a link back to this woman," Reese said of the alleged prisoner swap. "This is just another way to help them (ISIS) bring these people back and help with their propaganda."

In February 2014, al Qaeda renounced ties to ISIS after months of infighting between ISIS and another group, al-Nusra Front. ISIS started in 2004 as al Qaeda in Iraq with the aim of creating an Islamic state across Sunni areas of Iraq and in Syria.

After the Jordan attacks, Muasher told CNN that al-Rishawi was not wearing an explosives belt when she was apprehended, but two belts were found with her. One was filled with the explosive RDX, the other with ball bearings, a technique used by the other bombers.

"The aim was to inflict the largest number of casualties," he said.

Muasher said Jordanian authorities had information that al-Rishawi's husband "asked her to step out of the room" when her explosives failed to detonate.

In her confession, al-Rishawi said she and her husband stood at opposite sides of the room for the double-bombing.

"There was a wedding ceremony in the hotel," she said. "There were women, men and children."