Premise: Nannina de' Medici (14 February 1448 – 14 May 1493), born Lucrezia de' Medici, was the second daughter of Piero di Cosimo de' Medici and Lucrezia Tornabuoni. She was thus the elder sister of Lorenzo de' Medici. She married Bernardo Rucellai. Her father's name was Piero, so she is sometimes known as Lucrezia di Piero de' Medici.
Hypothesis: Nannina de' Medici was the first daughter of  Piero di Cosimo de' Medici and Lucrezia Tornabuoni