"Last message - under heavy bombardments now, can't be alive anymore. When we die, keep talking for 200,000 still alive. Bye."
At least a dozen civilians are believed to have been killed in the bombings. Bana's house was destroyed but her and her family survived.
She tweeted a picture of herself on Monday morning covered in dust with the words: "Tonight we have no house, it's bombed and got in rubble. I saw deaths and almost died."
The seven-year-old's account is disturbing but important viewing. She shares images and videos of bombs dropping on the city, proof of a deadly campaign denied by both Syrian and Russian forces.
Often she shares images of dead bodies covered in blood and dust - among them are children she grew up playing with.
Through her tweets, it becomes clear how the situation in Syria is deteriorating. Reports from journalists trapped in the city are further proof of that.
Al Jazeera spoke with a freelance journalist trapped in the besieged city. Mohamed Shbeeb said more than 500 people had died as a direct result of Russian air strikes and ballistic missiles.
He said food and emergency aid were dwindling and conditions meant no new supplies were able to enter the regions cut off from supply routes.
"All the hospitals in the city are out of service. So the injured are a risk as there is only limited medical aid available," Mr Shbeeb said.
"The situation is becoming worse every day. Food supplies have almost dried up. All stores are closed. Some people sell vegetables that they grow in their garden. Other food is no longer available."
UN food rations were distributed on November 11 but it's believed 275,000 people are trapped in freezing conditions, starving and under constant threat of artillery strikes.
There was some relief on Sunday, according to reports. The Syrian Observatory for Human Rights said as many as 400 civilians were freed from eastern Aleppo over the weekend.
Syrian state media said government forces had on Saturday captured Masaken Hanano, the largest rebel-held district of Aleppo, in what would be a major breakthrough in the regime's offensive to retake the entire city.
Fresh fighting broke out on Saturday night between regime forces and rebel groups in the neighbouring districts of Haidariya and Sakhur, said the Observatory.
Regime forces targeted the area with heavy shelling, said the Britain-based monitoring group.
Pro-government media hailed the "success" of the government forces, reporting that they continued their advance on Sunday.
The "success" means families like Bana's are without a home. But at least they're alive. AFP reports 27 children have been killed as part of more than 200 casualties since the government launched its assault on rebel-held Aleppo on November 15.