what was her character like? was she a loving woman or a pain in the neck?
According to Dansk Biografisk Lexikon she was neither. Her reputation has mostly been stained by how her relatives, some of them not admirable persons obtained a lot of government positions and influence. Even though Anna Sophie was a carefree, gay woman with an inclination to intrigue, such doings can of course not exclusively be blamed on a young woman who seems to have loved her husband devotedly. Her father was already Grand Chancellor of Denmark and her sister, among her numerous siblings was the ancestrerss of two powerful comital families: The Frijs of Frijsenborg and the Holsteins of Holsteinsborg. (The latter no relations to the Dukes of Schleswig-Holstein.) One other sister was married to a Count Danneskiold-Laurvig, her brother to a Countess Danneskiold-Samsøe. (Both morganatic lines of the RF!) So one can imagine this "Reventlow gang" as they were called, pressing their highest-placed relative for favours....
In her own time it was of course the scandalous marriage that stained her reputation: There was death penalty for bigamy for everybody except the "Hereditary Absolutist King", who was above the law. When he finally married her to the right hand, it was on the day after his right-hand queen's funeral! Her stepchildren hated her and Christian VII broke the promise he had given his father that he would take good care of her. Instead she was banished to a very comfortable retirement on Clausholm in Jutland. There she became very religious, pondering her sins (she believed that the fact that all her children had died as babies was God's punishment) - a Pietist, just like her stepson Christian VII. His queen, from a tiny German principality, of course also abhorred the fact that Anna Sophie was a mere, noble countess and not of princely stock.
BTW Woolworth heir Barbara Hutton's husband Count Curt Hardenberg-Haugwitz-Reventlow, discussed in
this thread was descended from Anna Sophie's brother. Count Christian Ditlev Reventlow. From his first wife, a Brockdorff, he acquired Krenkerup, the manor on Lolland that might have been the Danish castle where Barbara Hutton and her husband lived for a while. BTW Krenkerup has not been subjected to a sale since the 14th century, only inherited! Truly aristocratic!