In the time of Jeremiah the queen of heaven was the Assyro-Babylonian Ishtar. Inasmuch as there were immoral ceremonies connected with this worship, it aroused Jeremiah’s hot indignation, particularly since it appears to have been a prominent part of the idolatry then practiced. The Assyro-Babylonian Ishtar, the mother goddess, was the equivalent of the divinity known to the Hebrews as Ashtoreth and to the Canaanites as Astarte, whose figurines are found in Palestine. This goddess of fertility, of maternity, of sexual love, and of war was worshiped in rites of a grossly immoral and debasing character. She was essentially the same goddess though worshipped under many names and in many aspects, such as the earth-mother, the virgin-mother, and is identified in a general sense with Atargatis, the “Great Mother” of Asia Minor, Artemis (Diana) of Ephesus, Venus, and others.
Roman Catholics today call Mary the Queen of Heaven, but this has nothing to do with the queen of heaven in Jeremiah’s time.
-- Gerhard Pfandl, correspondence