The mother of Palestinian toddler Ali Saad Dawabsha, who was killed when suspected Jewish extremists firebombed his house, succumbed to her injuries on Sunday night, said the Israeli hospital where she was cared for and her family.
Several suspects have been arrested after the family's home in the West Bank village of Duma was firebombed with Molotov cocktails on July 31, sparking anger among the Palestinian community.
"Riham Dawabsha died in the night," a spokeswoman for the Tel Hashomer Hospital in Tel Aviv told AFP, where the 26-year-old teacher was admitted with third-degree burns covering 80 percent of her body.
Anwar Dawabsha, a family member, confirmed he had been informed of her death and said the funeral would be held on Monday in Duma.
Riham Dawabsha's death comes after her 18-month-old Ali died on the day of the attack and his father Saad eight days later. Ali's four-year-old brother Ahmed is still in hospital.
The Israelis are expected to return Riham's body to the Palestinian authorities to a checkpoint at the entrance to the occupied West Bank, from where it will be taken to her village.
The family's small brick and cement home was gutted by the fire and a Jewish Star of David spray-painted on a wall along with the words "revenge" and "long live the Messiah".
The bombing came only hours after a stabbing attack at a Jerusalem Gay Pride march that killed a 16-year-old girl and wounded five other people.
While the attacks were not related, both have led to criticism of Israel's government and security forces, who have been accused of failing to tackle Jewish extremism.
Thousands of mourners, many waving Palestinian flags, turned out to lay Saad Dawabsha to rest last month in an emotional ceremony that later erupted into clashes with Israeli border police.
Prime Minister Benjamin Netanyahu has pledged to tackle the issue and labelled the firebombing "terrorism" -- a word usually reserved by Israelis for violence by Palestinians.
The Palestinian foreign ministry in the West Bank city of Ramallah said it had submitted a request to the International Criminal Court to probe the firebombing and "settler terrorism".
There has been a series of nationalist hate crimes, known as "price-tag" attacks, by suspected Jewish extremists.
Such groups have warned in the past there would be a price to pay for any action by Israeli authorities they regard as hostile to the Jewish settlement movement or to far-right religious beliefs.
Last month, a tent was torched and Hebrew-language graffiti sprayed in a Bedouin village in the occupied West Bank in what residents and an NGO said was another suspected attack by extremists.
The village is near a wildcat Jewish settlement outpost where police detained several people in raids linked to the July firebombing, before later releasing them.
The graffiti, which read "administrative revenge" seemed to refer to the internment without charge -- known as administrative detention -- of three alleged Jewish extremists after the July 31 arson attack.
The suspects have not been publicly accused of the Duma firebombing, but of unspecified links to a "Jewish extremist organisation".