Bertin made several journeys abroad during the Revolution, which attracted attention. She made a trip to England and Germany in 1791–92, leading to suspicions that she was acting as Marie Antoinette's agent. According to these speculations, she secretly visited Francis II, Holy Roman Emperor to deliver a message from Marie Antoinette, as the latter's correspondence was scrutinized and an oral message through a loyal messenger was regarded as the safest method to deliver a sensitive message across borders. This is unconfirmed, but not improbable, as the queen is confirmed to have used her hairdresser Léonard Autié as a messenger during the Flight to Varennes, and it is noted that Henriette Campan claimed that the queen managed to get secret messages to her nephew the emperor during this period. Officially, these were business trips, and Bertin is confirmed to have been in Germany in July 1791, when her presence is noted at the French émigré court in the Castle Schoenbornhut in Koblenz, where she was said to have contributed to the extravagant fashion of the women attending the court.