It's a woman's prerogative to change her mind.
Britt doesn't care for her friend's plan to fix her up with a total stranger that weekend. However, when sinfully sexy Harrington appears, she reconsiders her objections. The script is fine. It's the cast that needs to change.
After meeting the man intended for her, she knows she's right. Only the butler has bothered to ask what she wants. Her answer is simple. Him.