Canada has captured third place in both tournaments on the women's sevens tour this season, beating France in the third-place game both times.
Canada has 32 points after two events, good for third place on the circuit behind Australia (36) and New Zealand (40).
Ghislaine Landry also scored a try for Canada in the third-place game. The Toronto native has 99 points this season, the most in the series.
New Zealand beat Australia 17-10 in the championship game.
Canada was close to advancing to the final in Sao Paulo, dropping a 12-7 semifinal to Australia.
Canada led 7-5 with two minutes to go on a converted Landry try, but the Australians capitalized on a missed tackle and scored a try just as the final whistle sounded.
In quarter-final action early Sunday, Canada beat Russia 22-10.
Farella and Landry had two of Canada's tries, with Jen Kish and Karen Paquin scoring the others.
The women's sevens series shifts to North America, with tournaments March 14-15 in Atlanta and April 18-19 in Langford, B.C.