Ralph Keeney and Dinah Vernik of Duke University have produced an elegant model of the 'biological clock' decision. Implemented in Excel and publicly available, the model allows a woman to work out the optimal timing of their first birth (assuming other necessary conditions are met!) by expressing their beliefs and preferences in relation to their entire Professional Life, Social Life and Family Life - where Social Life is defined to exclude that inside the family. If a woman is able to work her way through the model and make the many (93) assessments necessary they will identify the first birth timing that takes into account all her beliefs and preferences - and those of her partner if the task is tackled jointly. If this is too demanding we offer a more simplified model of the biological clock in Annalisa which requires many fewer assessments but hopefully still offers important insights. This 'starter' Annalisa assumes the woman is 20 and is contemplating her 3 lives up to the age of 80. These lives are divided at 50 to give two thirty-year periods. (As in any Annalisa these assumptions could be easily modified to fit any particular individual circumstances.)