IGI shows two possible children for Anne and John (listing parents as John McGuire and Ann Fox):
Hugh, b. 8 Jun 1865, Banbridge, Co. Down.
Rose, b. 17 Feb 1870, Co. Down
http://0-www.aucklandcity.govt.nz.www.elgar.govt.nz/dbtw-wpd/passengers/passenger.html shows, arrived 1885 on the Doric:
Maguires:
Ann, Emms, Hugh, James, John, Maggie, Mary.
alternatively, arrived 1883 on the Langstone:
Ann, John, Joseph.
Also the cemetery database shows an Annie Maguire, buried at Waikaraka, wife of John, died in 1908 aged 69 or 70. Also her husband John died in 1912 aged 80.
1881 Electoral Roll of Auckland does not show a John Maguire or a William Fox.