Her e-commerce store "Lily's Easel" opened in February on social networking app WeChat and she sold her first painting on the second day, for 360 yuan.
The buyer was captivated by the artwork and told Zhang he would cherish it, a comment that moved her to tears.
In the first two months, she sold dozens of paintings and also started to receive custom orders.
Not all the buyers knew about her condition at first, but after finding out they have been universally encouraging, Zhang said.
Still, her physical condition worsens day by day and she is mentally prepared for the end.
"I pray to God every day for more time. I am not greedy, I just want to have painted for 10,000 hours. That is my dream," she said.
Contact the writers at liyang@chinadaily.com.cn