Jesper Holmris’ side failed to capitalise on a fine start as they lost 30-17 to Brazil in front of another passionate crowd at the Copper Box.
France-based Gerbron believes they will continue to improve as they face Angola – a team the British have targeted as a scalp.
“We are still doing mistakes we shouldn't be doing,” said the 25-year-old. “The defence was much better and we are trying really hard.
“We haven’t spoken about Angola yet. We are just taking every game as it comes. We are gaining more and more experience.
“The crowd we really amazing and supportive even when the score is such a big difference.
“People are really impressed with the sport and that is what we wanted to give the Great British public.”
Great Britain didn’t get off the mark until the fourth minute, when Gerbron and Britt Goodwin both scored to make it 4-2 to Brazil.
However, the defence, which had looked shaky in their first two games, stood firm and only conceded six goals in the first ten minutes.
Team GB were still guilty of errors that cost them clear chances, but this was the best performance of the Games so far, with goalkeeper Sarah Hargreaves helping to keep them in touch with some fine saves.
But a needless suspension for Goodwin – after she tried to tackle above the neck – impacted on Great Britain, who became ragged and allowed Brazil to post a 17-8 half-time lead.
Great Britain made another flying start to the second half, and a penalty for Gerbron brought up double figures as the Brazilians led by eight.
But Holmris’ side continued to allow Brazil to shoot from the nine-metre line, leaving Hargreaves exposed in goal as the hosts found themselves 21-12 behind.
Lyn Byl continued her good form of the tournament as she worked the Brazil defence on the line, but she it was in isolated bursts as Brazil saw out the game.
The 32-year-old, who left top-level handball with Bayer Leverkusen in Germany’s Bundesliga for the Team GB programme, believes the poor performance meant it was a missed opportunity for Great Britain.
She said: “I’m disappointed because I thought it could’ve been a closer game. There were too many technical mistakes. We weren’t prepared for their 5-1 defence.
“We were too nervous. In the beginning, it was close but then we couldn’t score and gave away too many goals.”