The Scorsolini marriage bargain

Principe Claudio Scorsolini's future wife must make a suitable figurehead for his people and provide him with an heir. Claudio's convenient union with Therese is hailed a success: his subjects have fallen in love with her and she's performed her duties in the bedroom -- to Claudio's "immense" satisfaction. However, Therese has secretly fallen in love with her husband. How can their marriage survive when she knows she can never give Claudio a child?