Possible Clues:

• Overwhelm single sister with fruit
• Overwhelm one sister before romantic get-together
• Romantic meeting at pub interfered with by mid-January flood
• Overwhelm one with a sister, see?
• Flood in a French department at the end of June
• Overwhelm one lady with habit to see men?
• One must attend appointment with pigeon in swamp
• Overwhelm single sister over engagement
• Overwhelm island court holding sister
• More than fully cover