The militant group Islamic Jihad said the attack was in retaliation for the deaths of several of its leaders in Israeli raids.
Jaradat left home on Saturday at about 7.30am, earlier than usual, and did not tell anyone where she was going, her family said.
Despite restrictions Israel had imposed over the West Bank to prevent attacks before the Yom Kippur holiday yesterday, Jaradat managed to slip into Israel.
“The only thing that would push her to do that would be to avenge my brother’s death,” her brother, Thaher, 15, said. On June 12, Israeli troops who had come to arrest her cousin Salah, an Islamic Jihad militant, killed him and her brother Fadi.
She heard the shots and ran outside to help, but the soldiers shooed her away.
Jaradat, who had finished legal studies in Jordan five years ago, was supposed to finish her apprenticeship next