SIGNORA DA VINCI by Robin Maxwell

Another book from my selection for the Historical Fiction Readiing Challenge on the royal reviews blog
This story tells of Caterina, the mother of Leonardo da Vinci.
From her humble beginnings as the daughter of the local apothecary in the village of Vinci, we follow her life as she falls in love with the son of the local aristocrat family, Piero da Vinci.
But when she falls pregnant and believes that Piero will marry her, she is sadly disappointed.
When the baby, Leonardo is born, the family (Da Vinci) takes the baby to live with them, as was the custom.

Over the years, Caterina finds ways to spend time with Leonardo, with the help of Francesco, Piero's brother.
Piero wants nothing to do with the child and the family sends Piero to Florence to make a suitable match befitting his position as a Notary.
When Leonardo is only about 11, Caterina requests Piero find an apprenticeship for Leonardo, as due to the custom of the time, illegitimate sons coud not follow the profession of the father.

Thus Leonardo finds himself apprenticed to ne of the masters in Florence, where his talents develop. Caterina misses him so much, that her father suggests she go to Florence, where he has an apothecary shop which was bequeathed to him by his former emplyer. There she can set up shop, but she will have to disguise herself as a man.
Due to her father's teaching since she was a young girl, she is well education in the arts etc and so she is able to assume this change and revels in it.
She has so much more freedom than living as a woman, and is now known as Cato. By chance she makes the acquitance of Lorenzo De Medici and is drawn into the illustrious circle. Eventually falling in love with him.

Very good insight into that time in history.