She played for Scotland in the Women's Home Internationals and the European Ladies' Team Championship, and represented Great Britain & Ireland in the 2008 Curtis Cup.

In 2015 she recorded a victory at the Ribeira Sacra Patrimonio de la Humanidad International Ladies Open in Spain, and finished 8th in the Order of Merit.

[1] On the LET, Thomson was runner-up in the 2017 Hero Women's Indian Open, 1 stroke behind Camille Chevalier of France, to end the season 16th in the rankings.

[1] Thomson won a silver medal in the mixed event at the 2018 European Golf Team Championships at Gleneagles, together with a Great Britain made up of Connor Syme, Liam Johnston and Meghan MacLaren.

In 2020, she made her breakthrough with victory in Saudi Ladies Team International alongside Emily Kristine Pedersen and Casandra Hall.