Nelson McCausland's mention of Angela Lansbury and her Belfast roots set me off on a little tour of the internet and other resources this afternoon. Angela's mother was Charlotte Lillian McIldowie (1895-1975), better known by her acting name Moyna Macgill.
Charlotte, aged 5, appears in the 1901 Irish Census in Cranmore Park, Belfast, along with her solicitor father William (aged 37, Presbyterian, born Co Down), mother Elizabeth Jane (aged 33, nee Mageean, born Co Antrim) and siblings James Mageean (aged 8) and Margory Graham (aged 4 months). Elizabeth Jane was born on 17 May 1867, the daughter of James Mageean and Margaret Graham; her parents were married in Drumbo, Co Down, on 21 September 1860.
Charlotte, by then aged 15, doesn't appear in the 1911 Irish census, nor does her mother and brother James, but by this time other members of the family are now living in Deramore Avenue: William (47, born in Belfast, married 19 years, four children born and still alive), Marjory Graham (10, born in Bangor, Co Down) and Dennis William (7, born in Belfast).
PRONI Will Calendars provides the following abstract for William: McIldowie William of Sandymount Deramore Drive Belfast solicitor died 30 September 1929 at Westgate-on-Sea [Kent] Probate Belfast 23 June to William Hunter solicitor's assistant. Effects £16903 7s.
The Lennon Wylie website sheds additional light on the whereabouts of this McIldowie family with the aid of Belfast street directories:
1880 - McIldowie, George, Hopeview Cottage, Strandtown, Co Down
1907 - McIldowie, G., & Sons, Solicitors, 26 Corn Market; res., G. McIldowie, 31 Kirkliston Drive; George McIldowie, jun., Elphinstone, Craigavad; and William McIldowie, Sandymount, 23 Deramore Drive
1910 - McIldowie, G., & Sons, Solicitors, 26 Corn Market; res., George McIldowie, jun., Elphinstone, Craigavad; and William McIldowie, Sandymount, 17 Deramore Drive
PRONI street directories yield:
1890 - McIldowie, George & Sons, 26 Corn Market - George, George jnr and William, Kin-Edar, Strandtown.
1895 - McIldowie, Wm of Geo McIldowie & Sons, 3 Tudor Gardens, Eglantine Avenue.
"Scots Kith and Kin" refers to the McIldowies as septs of the MacLeans of Duart, Cameron, Lamont and MacGregor.
Scotland's People: "The gaelic Mac Ghille dhuibh, or “son of the black lad”, seen in the surnames Macilduy, Macildue and Macildowie, translates to Black".
Charlotte's grandfather, George McIldowie, is recorded in the 1901 census. This George (aged 64, solicitor, living in Sydenham Avenue) was born in Paisley, Scotland; his wife Charlotte Mantell (aged 60) was born in Irvine, Scotland; their son Louis Mantell McIldowie [born 08 March 1877 - familysearch.org] was one of the inventors of a new apparatus for cleaning windows whilst living in London. Belfast Cemetery records - City Cemetery: Charlotte, Belgravia, Kirkliston Drive, Bloomfield, died 21 September 1908, aged 68; George, Fountainvale Avenue, died 29 November 1910, aged 74.