This book was set in 1487, which is the same year that the farcical witch-hunters' manual Malleus Maleficarum was published, and Leonardo da Vinci drew his 'Vitruvian Man'. It tells the story of Giulia Borromeo, the daughter of a Count and a seamstress in his employ.
When the count dies, it turns out that in his will, he has left provision for a dowry for Giulia so that she might marry decently, but her wicked stepmother decides that Giulia needs to be married to Christ, and gives her dowry to a convent, to which Giulia is promptly dispatched. She's not sent so promptly however that she doesn't have time to pay a quick visit to an astrologer who maps out her future with regard to whether or not she will ever meet her romantic match.
If she'd worded it precisely that way, she might have got a clearer answer, but in a desperate attempt to make sure she gets what she wants, she also pays a sorcerer to create an amulet containing a spirit which will guide her to her true love. I'm unconvinced of the value of incorporating this supernatural element into this story, because it seemed like an unnecessary distraction to me, and the story works perfectly well without it, but the amulet played only a small role, so I was willing to let that slide.
That amulet seems to Giulia like it burns when she meets a young man at the monastery who is there to renew a damaged fresco. Of course she's not supposed to be with him alone, but she's a bit of a rebel, and she doesn't want to be at the convent anyway. She has other plans. She's expecting to meet the love of her life and move on.
Later, she meets the same guy on a supervised trip from the convent. This trip came about because Giulia has some talent for drawing, and the convent she was sent to conveniently has a workshop of some renown, where nuns create works of art to adorn churches. It's quite a lucrative business, especially since one of the nuns - the maestra, has created a brilliant shade of blue known as passion blue - not from romantic passion but from the passion of Christ. Once Giulia's skill in art comes to light, she's is adopted by this maestra, and begins training as an artist under her wing. She attends the workshop each day instead of pursuing what the other nun novices are doing.
Despite being thrilled with her opportunities there, Giulia is still intent upon pursuing her romantic inclination, and she secretly arranges to meet her guy in the orchard behind the convent one night, where there's a breech in the wall and he can climb through. These meetings continue, but they don't end up where Giulia was expecting them to!
The book was quite surprisingly entertaining. It felt really nice for a change, to pick up a book like this on spec as it were and to discover that it's as good as you'd hoped it would be. We should all write books like that. I commend this fully as a worthy read.