Just throwing the following birth into the mix, as a possibility for 'Maud Black' in the 1901 census, I haven't yet found a marriage for the parents...
Maude Maxwell, born at 3 Ballyclare Street on 26 June 1896, parents given as Samuel Maxwell of that address and Margaret Black, Rose Ann Black - also of that address - was the informant:
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_returns/births_1896/02164/1820082.pdf
Still couldn't find a marriage for Samuel Maxwell and Margaret Black, or any other children for them, so I went looking for a marriage for Margaret Black (to anybody) in the years immediately after that 1896 birth of Maude Maxwell and found the following marriage in Cliftonville Presbyterian Church on 31 October 1900 to a widowed carpenter called John McNee - Margaret is recorded as a spinster, the daughter of James Black a mill-wright:
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1900/10360/5771491.pdfBTW, note the above marriage witnesses - we've had the Harvey surname before (at reply #3 and reply #10), in relation to William Harvey marrying James Black's daughter Sarah Jane in 1920. I haven't yet found a birth for Margaret (ie. to James and Rose Ann), but the combination of the father's details and the witness names in the above 1900 marriage are persuasive that she was indeed another of their children.
Anyhow, below are John and Margaret McNee 5 months after their marriage in the 1901 census, John's mother is in the household, as is a daughter Ellen (presumably from his previous marriage), Margaret's age is 28:
http://www.census.nationalarchives.ie/pages/1901/Antrim/Shankhill/Upper_Glenfarne_Street/950530/The couple had their first child Isabella in 1902, but lo and behold, by the time of the 1911 census, an older daughter "Maude McNee" has miraculously appeared:
http://www.census.nationalarchives.ie/pages/1911/Antrim/Clifton/Ballynure_Street/144239/So to me it looks like the 4 year old grand child Maud Black in the 1901 census return for house 1 in Ballyclare Street, may be the illegitimate child of James Black's daughter Margaret (the child registered as Maude Maxwell, father Samuel Maxwell), who then appeared back with her married mother as Maude McNee in the 1911 census return for house 6 in Ballynure Street.
Incidentally, when Maude married a William Hurst in Belfast in 1929, she did so as Maude
Maxwell, and gave her father as William Maxwell (which isn't consistent with the 1896 birth registration), and his occupation as fitter (which is consistent with the 1896 birth registration). Isabella McNee was one of the witnesses.
Edited to add: This looks like a McNee grave:
http://www.rootschat.com/links/01qy0/