I was an adventuress (1940)

Posing as the fabulously glamorous Countess Tanya Vronsky, a poor young ballet dancer and her two accomplices are really a team of skilled con artists! They mingle with Europe's high society, always looking for the next wealthy victim to fleece with their fake jewellery scam... Then Tanya meets the dashing young Paul Vernay. At first she wants to rob him. Then she decides she wants to marry him and to leave her criminal past behind her. Her accomplices agree but only if she'll join them in one last, big swindle...