Hi Alleson,
Here is the Intention to Marry Notice you requested. Please note that the name of the bride differs from the name you provided. I did see an ITM notice listed in the card index for a 'Margaret SHEA' for the following year, 1877, and registered at Wanganui.
Intention to Marry Notice. Archives NZ Ref: BDM 20/21 1876 Christchurch p.616/2741.
Dated 13 January: James MCGOWAN, bachelor, a Plasterer aged 21 years living at Christchurch, length of residence 1 year, intends to marry Bridget O’SHEA, spinster, a Servant aged 18 years living at Christchurch, length of residence 1 year, in the Scotch Church, Tuam Street, Christchurch. Name & Relation of Person giving Consent in the case of a Minor: ‘There is no person having authority to consent.’ Minister: Rev. C.FRASER. Marriage certificate reference number: 76/526.
Spades