Hi LU,   i  thought the record of the ship might be useful!, also the name May is used alot in Scotland for mary!
                 George Canning
Otago Witness – Saturday December 5, 1857 page 4 
Shipping News 
Arrived, November 28, George Canning, 411 tons, barque, Captain Sims, from London to Port Chalmers. Sailed on 23rd August. Made a good passage of 97 days, port to port.  She was the first in a series despatched by the emigration agent, James Adam, who had been sent home from Otago. 131 Passengers: 
Buskin      Mary A and 2 children
Blair      Robert age 46 b. Ayrshire 1810.  Agnes Dick (wife), Robert, Agnes, Margaret, Janet and John (Robert farmed East Taieri Dunedin)
Borrow      Mr and Mrs T and 3 children 
Butlar      John Geo.
Calder      C
Cahill      Thomas
Carless      John, Patience, Patience, Emily, Hannah, William, John, and Frederick
Cassells   Thomas, Janet, Margaret, Mary and Caroline
Cavanagh   John and Anna
Chittock   Mr Fred and Mrs
Chittock   George and Emily and 4 children
Clarke      Mr
Cockrill   Richard
Dunkley      Dennis
Fairmaid   Mr
Finlay      Helen, Marion, Jean, and James
Ford      Mr J
Ford      William
France      Mr and Mrs C and 3 children
France      Mr and Mrs J and child
Gough      Mr and Mrs R
Hammond      Charles, Sarah, Dinah, Martha, Richard Lates and Thomas Herbert Hammond
Hepburn      Mr and Mrs A
Hepburn      W
Jago      John, Mary Ann, Maria, John, Mary Ann, Charles, Julia, Sydney and Alfred
Leckie      Stewart, Agnes, Stewart, Archibald, John, Elizabeth, Agnes, Helen, and James William
Lewis      Mr
McKenzie   Mr
McCree      J
McVey      Joseph
Mathie      Alexander, Priscilla, Agnes, Helen, Emy, Catherine, Alexander
Morris      Aaron
Morris      William, Ann, Sarah  Maria, Thomas, Elizabeth, and William 
Nairne      Mr
Paterson   D
Paterson   James
Perry      Edward, Elizabeth, Edward Jas., and Wm
Prime      H.G.
Russell      Mr
Senior      J
Shand      Mr and Mrs, Misses (2) and 3 children
Sinclair   George, May, Alexander, May, Agnes and John
Small      Mr
Smith      Miss
Stewart      Miss
Stone      F
Tilly      Chas. and Barbara
Wain      John, Mary Margaret, Frederick, Margaret Elizabeth
Wain      Ann Sophia, Joseph William, and Suhannah
Watson      Mr   
The foregoing list includes 2 tailors, 2 storekeepers, 1 servant, 9 farmers, 1 clerk, 1 butcher, 1 carpenter, 20 labourers, 1 engineer, 3 shepherds, 1 dairymaid.  
Per George Canning, from London:     2 cases books
   1 ditto apparel
  20 ditto glass
100 cases Geneva
 20 bundles square iron
 20 do. hoop iron
  51 camp ovens
  51 lids for ditto
    1 coil rope
    1 case seed
    1 box books
    2 casks whiskey
    1 case clothing
  42 tons coal
    6 hhds. rum  83 cases soap
 20 kegs arsenic
   4 bars iron
   4 bundles ditto
   6 ploughs
   2 wheels
    1 axle
    3 parcels
112 casks
209 cases
  30 barrels
   6 trunks
 10 bales
 30 kegs
   4 boxes 
Saturday 26 Dec., 1857 Otago Witness
Sailed Dec. 18, George Canning, 411 tons, Sim, for Callao, in ballast, with one passenger.