The horns of her crown historically represented both the horns of the sacred bull (golden calf), and the Crescent moon. Notice the Red Sun between the Crescents. . . . . this is the Rising Sun.
The following explanation is a repeat from the photo one.
Isis... Ancient Egyptian goddess of fertility, and sister and wife of Osiris (Ba'al) the Egyptian god who was worshipped at his annual Death and Resurrection, which personified the self-renewing vitality and fertility of nature.
Here Isis is shown nursing her son Horus, who was worshipped as the "Sun god" or "God the Son."
This mother and son relationship was universal amoung pagan nations. Each nation would have their own name for their gods and goddesses, but they all adopted each others concepts. This was mainly due to one nation conquering another, and absorbing each other's cultures. Later, this pagan culture was absorbed into the (un)holy Roman Empire, and ultimately by the Roman catholic church. Notice the similarity between the catholic madonna (Mary) and the Egyptian madonna (Isis).
"Madonna" is the ancient Roman (Italian) title for a married woman.