Ba Lili and her daughter, Xiao Huixuan, comfort each other at a ward in Peking University People's Hospital in Beijing last month. [Provided to China Daily]

An 8-year-old girl is continuing to eat more in the hope of gaining enough weight to meet a requirement for transplanting bone marrow to her ailing mother.

Xiao Huixuan, from Shouguang, Shandong province, has already gained about 5 kilograms in less than two months after she learned she could be a donor match for her mother, Ba Lili, who was diagnosed with leukemia in 2015.

Of all Ba's relatives, only the daughter was a suitable match.

The girl, who can only donate after she weighs at least 30 kg, now weighs 29 kg.

After two months of bulking up, Xiao underwent bone marrow extraction on Feb 14 for tests at Peking University People's Hospital in Beijing. Because of her age, she could not have any anesthetic.

Han Tingting, the doctor overseeing the treatment, said the test results will be available in one or two weeks. She said there is a possibility the girl might not be able to donate if certain key test results don't meet the requirements.

"No matter what the final result is, the girl is very courageous to donate for her mother,"she said.

Han said she will not initiate any transplant process if the girl's body fails to meet the requirements.

Xiao said the extraction was painful. "I tried my best not to cry because my mother would be sad if she heard me crying."

Ba recalled:"When Xuanxuan (a pet name for her daughter) got out of the room, she was sweating as she tried hard to endure the agony. However, she told me it was not painful.

"Once I told her to be optimistic about life, even if something wrong took place during my surgery. Xuanxuan hugged me and encouraged me to be brave,"she said.

"Xuanxuan often gives me a massage to relieve my pain and she often says, ‘I love you, Mom' to make me confident."

Ba said she has been cared for by many kindhearted people including doctors, nurses and strangers who have donated money.

Xiao said: "I will endure all of the agonies as long as my mom can survive. I love my mom, and I have to save her."