Below is a chart showing the vital information in the 1800 census for the household of Daniel Donnall/Donnell (#105).
The names of all of the family members cannot be known for sure, but the white male under 10 was likely his son Ervin (#53), born in 1793 and ~7 years old. The free white male 10 thru 15 was likely his son Joseph, born in 1790 and ~10 years old. The two free white males 16 thru 25 were likely his sons Robert, born in 1778 and ~22 years old, and Daniel, born in 1784 and ~ 16 years old. The free white male 45 and over was Daniel Donnall/Donnell (#105), born in 1755 and ~45. The free white female under 10 was likely his daughter, Martha, born in 1782 and ~8 years old. The free white females 10 thru 15 and 16 thru 15 are unknown. The free white female 45 and over is Daniel's wife, Mary Ervin Donnell (#106). She was born 1760 and would have been ~40 years old. Including the six slaves, there were 15 people in the household.
Below the chart is a scan of the actual census that shows Daniel Donnall's name highlighted in red. Note this partial census page includes many other Donnalls: William, Latham, John Senr., Andrew, Robert, Thomas, and George. William, George, and Robert were names of Daniel's brothers, and brothers George and Robert may have been the men on this census. But this William was not Daniel's brother. The History of Buffalo Presbyterian Church and Her people, page 125 states that William Donnell, the oldest son of Robert, the second. He married Mary, the daughter of ruling elder Samuel Bell, in 1773. He moved to Tennessee in 1797, and died in 1798." So this statement proves the William in this Guilford County Census was not Daniel's brother.