The 31-year-old, who was ninth after the first run, cleared four gates in the giant slalom but ended up wrong at fifth, lost a lot of time and ended up twelfth in a snowy and windy Canada.
A result that is her worst this Alpine World Cup season.
Since earlier, most recently on Saturday, Hector has been fourth on four occasions and at worst ninth.
Hilma Lövblom was 19th skier.
Estelle Alphand and Lisa Nyberg did not make it to the second run.
Federica Brignone, Italy, won on Saturday and then took home the victory on Sunday ahead of Lara Gut-Behrami, Switzerland, and Mikaela Shiffrin, USA.