One of the main issues in their relationship is Birdy's refusal to conform to the expectations of a medieval woman. Lord Rollo wants Birdy to marry a wealthy man and settle down, but Birdy has other plans. She is intelligent and curious, and she dreams of a life of adventure and freedom.
Another problem in their relationship is Lord Rollo's financial situation. He is in debt, and he sees Birdy's marriage as a way to improve his fortunes. Birdy is aware of this, and she resents being treated as a commodity rather than a person.
Despite their differences, Birdy and Lord Rollo do love each other. However, their love is often overshadowed by their conflicts. Birdy longs for her father's approval, but she is also determined to live her own life. This tension between love and duty is a major theme in the novel.