Esme was a French Resistance fighter in Paris (along with Jean-Paul) who for years helped bring down The Façade that was Perfect Paris.
She captured Rose Tyler and took her through a Glitch to the real Paris. She then became angry with Rose when she commented that the Facade was good, Esme responded by saying that only real things where good and walked off. She eventually helped Jean-Paul to rebuild Paris. (DWAM: A Date to Remember / Snow Fakes)