Ladies:

• Agatha > "Aggie"
• Catherine > "Cato", "Cathy"
• Delphine > "Delphy", "Elfie"
• Dorothy > "Dolly", "Dodie"
• Isobel > "Ibb"
• Marceline > "Marcy"
• Marguerite/Margaret > "Maggie"
• Marjorie > "Margie"
• Salomé > "Sally"
• Sebastiane > "Sebbie"

Gentlemen:

• Christian > "Cat"
• Elliott > "Ellie"
• Gabriel > "Gaby"
• Gregory/Grégoire > "Grishka"
• Ralph > "Ralphie"

Either/neither:

• Laurence > "Laurie"
• Winifred > "Winnie", "Wolf"