I had a quick look for the family in 1911 census to see if there were children/children's birthplaces listed but couldn't find them (it does help to give a link to details you've found).
From records I found it would seem that they probably moved from Co. Tyrone to Belfast between 1877-1880.
Seven daughters listed in IGI (
www.familysearh.org) with mothers name spelt as Mains/Maynes:
1. Mary Jane born 15 Dec.1866 Six Mile Cross, Co. Tyrone
2. Rose born 26 July 1868 Co.Tyrone
3. Mary born 10 Oct.1870 Co.Tyrone
4. Teresa born 15 Nov.1872 Co.Tyrone
5. Elizabeth born 3 Oct.1874 Aldrumman, Co. Tyrone
6. Alice born 27 Oct.1877 Co.Tyrone
7. Catherine born 6 Oct.1880 Belfast, Co.Antrim
Civil registration of births and Catholic marriages so there could be other children born before 1864 and if the parents were married in a Catholic before that date you'll probably need to search for church records.
If it was a Catholic marriage (after 1864) or Registry Office one (after 1845) it should be listed in civil index:
http://pilot.familysearch.org/recordsearch/start.html#p=collectionDetails;t=searchable;c=1408347Added: 'Adrumman' is probably the townland of Altdrumman in Termonmaguirk civil parish (Omagh Poor Law Union), Six Mile Cross is in the same parish.