Thornley won the women's single scull 5km trials race in Boston, Lincolnshire in November, but there are doubts over her double sculls place.
She has been competing alongside Scotland's Katherine Grainger, having been in the women's eight at London 2012.
They are regarded as the fastest individuals, but questions have been raised over their double sculls combination, with the pair only finishing sixth at the World Championships in Aiguebelette this year.
Helen Glover and Heather Stanning, who won GB's first gold at London 2012, will continue in the pair for Rio.
However, Thornley believes continuing to impress in the build-up to the Games can secure her a place in Brazil.
"I will want to be in the boat with the best chance of winning a medal," she said.
"I was really pleased with the weekend. I won the trial in November so wanted to keep myself at the top of the team in the singles results.
"I did that and had a good margin over the second place."
She added: "Fundamentally it comes down to what the coaches feel they want to prioritise.
"But the better results you have, the more sway you might have over the decisions that are made."