The education ministry said third-grade student Ritaj Rihan was hit by a bullet in front of her classmates, causing them "a strong psychological shock".
Health officials said three other Palestinians were killed in two separate airstrikes in northern and southern Gaza Strip, bringing Thursday's death toll to at least four.
Medics said an Israeli airstrike near a hospital in Jabalia, in the north of the enclave, killed at least two people, while another strike killed one person in Khan Younis, in the south.
The Israeli military did not immediately comment on any of the incidents.
Under a ceasefire in place since last October, Israel still occupies more than half of the Gaza Strip. Nearly all buildings in the Israeli-controlled sector have been levelled and residents driven out.
That leaves virtually the entire population of more than two million people confined to about a third of Gaza's territory, mostly in makeshift tents and damaged buildings, where life has resumed under the control of an administration led by Hamas.
Displaced Gaza children are attending classes given by volunteer teachers in crowded tents in some areas, keen to continue their education despite the widespread destruction of schools.
These makeshift classrooms face severe challenges, including harsh weather, resource shortages, and security risks.
More than 700 Palestinians have been killed since the October deal took effect, while militants have killed three Israeli soldiers.
Palestinians say Israeli forces have been moving some of the yellow concrete markers westward, encroaching into unoccupied territory. Israel denies this.
Israel's assault on Gaza has killed more than 71,000 people, according to the enclave's health ministry. The war was triggered by a Hamas-led attack on southern Israel on October 7, 2023, which killed some 1,200 people, according to Israeli tallies.
