Readings has said their target is gold - "people might laugh but we would rather aim for that and not achieve it", he said - but they have a decent chance of at least progressing out of their group.
In addition to Great Britain, the Football Ferns will also take on Brazil and Cameroon. The top two sides from each group in the 12-team tournament, as well as the two best third-placed teams, will advance to the quarter-finals.
One win is a minimum requirement and the final pool match against Cameroon on August 1 looks the best chance.
New Zealand have been in good form of late. They recently beat China in two games - the first time the Ferns had ever beaten the former superpower of women's football - and Wednesday's 2-0 defeat to Australia snapped a nine-game unbeaten streak.
Most of the Olympic squad went to last year's women's World Cup but former New Zealand women's cricket international Rebecca Rolls, who claims the second goalkeeper spot, and 19-year-old former Australian age-group representative Rebekah Stott have earned selection.
Striker Rosie White, the other teenager in the squad, has fought her way back from a stress fracture and is one of eight squad members aged 24 or under.
New Zealand squad: Goalkeepers: Jenny Bindon (Hibiscus Coast), Rebecca Rolls (Fencibles United); Defenders: Ria Percival (USV Jena, GER), Anna Green (Lokomotiv Leipzig, GER), Abby Erceg (Fencibles United), Rebecca Smith (captain, VfL Wolfsburg, GER), Ali Riley (Malmo, SWE), Kristy Hill (Eastern Suburbs), Rebekah Stott (Melbourne Victory, AUS); Midfielders: Katie Hoyle (Bad Neuenahr, GER), Hayley Moorwood (Chelsea, ENG), Kirsty Yallop (Vittsjo, SWE), Betsy Hassett (UC Berkeley, USA), Annalie Longo (Three Kings United); Forwards: Amber Hearn (USV Jena, GER), Sarah Gregorius (Bad Neuenahr, GER), Rosie White (UCLA, USA), Hannah Wilkinson (Glenfield Rovers).APNZ