The daughter of painter Guglielmo Caccia and Laura Olivia, she was baptized Theodora Orsola on December 4, 1596.
[4] At the time, Bianzé was a fortified outpost on the frontier between the lands of the Gonzaga, the dukes of Mantua and Monferrato, and the duchy of Savoy and was often in the path of warring armies.
[4] To find a safer home for his daughters, Guglielmo requested and received permission to found the Ursuline convent at Moncalvo.
Her father died a few months after the convent was established and left drawings, set squares and other art tools for his daughters.
[4] Out of his six daughters and two sons, Orsola and her sister Francesca, who died at a young age, were his only two children to become painters.
[6] In two letters addressed to Christine of France written in 1643, she asked to be given an opportunity for paid work as her convent was suffering from poverty.
[5] Most of her works convey the repertoire of figurative models and types of composition that she studied in her father's studio during her adolescence.
Three women look after Mary's mother Anne who is lying on her bed after labor while three others prepare to wash the newborn child and heat pieces of cloth at a fire.
For example, a table on the left side of the image has an elaborate, coiled amphora and a tray of fruit with a cut lemon.
Also, a young woman who is advancing towards Anne's bed holds a jug of wine and a drinking glass on a round dish.
The atypical horizontal format of the painting suggests that it was meant to be set above a door, inserted in a wooden paneling of a wall, or to adorn a cabinet in a sacristy.
The objects seem to be laid out on a windowsill set in a wall of a room that opens out onto a view of the sky which is flecked with gray clouds.
The image stands out for its depiction of unusual species of plants and animals and its rhythmic composition which is formed around the alternations of color.
She also faithfully reproduces a large mushroom of the woodland clavaria species with its white, fleshy stem and yellow-ochre clustered branches.