How was the Virgin Mary depicted in the Middle Ages and the Renaissance?

During the Middle Ages, representations of the Virgin Mary developed into certain well-known types. For example, the Virgin Hodegetria held the infant Jesus in her left arm and pointed towards the child with her right, indicating the way to salvation. In the Virgin Eleousa, Mary's more compassionate and soft side is emphasized, as she touches her cheek to that of the infant Jesus, and he encircles her with his arms. 
Western representations of the Virgin, such as Throne of Wisdom (12th century), were influenced by Byzantine representations. During the Romanesque period, Mary's regal aspect was emphasized. She was often pictured wearing a blue cloak that also covered her head and was often surrounded by a halo. An example of this type of painting includes the Madonna of humility (a famous example of which was created by Dominico di Bartolo in 1433). The Madonna of humility often sits on the ground and cradles her son. During the Gothic period, Mary was depicted as a maternal figure who cared for her son. For example, the Rest on the Flight to Egypt, c. 1510, by Gerard David, shows the Madonna bestowing care on her infant son. 
During the Renaissance, Mary was sometimes painted alone in scenes representing the Annunciation and other scenes, but she was more often portrayed along with her infant son in poses that convey her tenderness. In addition, the Pietà, in which Mary is shown holding the dead body of Jesus, gained popularity (examples include that by Michelangelo). These works were often meant to evoke compassion and depict Mary in a state of grief and suffering--and therefore to show her human (as opposed to her regal) side. In many works of art in the Northern Renaissance, Mary was depicted as the ideal mother who nurtured Jesus, and she was intended to be a role model for women. 
https://www.metmuseum.org/toah/hd/virg/hd_virg.htm