[1][note 2] She was the eldest daughter of Count John IV of Nassau-Siegen and his wife Lady Mary of Looz-Heinsberg.

As a morning gift, Philip obligated himself to allocate her 200 guilders annually, which Anne was allowed to use as she saw fit after his death, for example for the salvation of her soul.

This dowry consisted of the income from her dower in the Duchy of Brunswick-Lüneburg, the District of Lüchow, which she leased for a sum of 666 guilders annually.

A priest accused of multiple murders, Johann von Börnich, confessed that, at the instigation of close confidants of the Landgrave of Hesse, he had given her a goblet of poisoned wine at a service he celebrated[1][10] in the chapel of Rheinfels Castle in Katzenelnbogen in January 1474, allegedly before the marriage.

[1] Because Anne's father instituted criminal proceedings against von Börnich, Hesse's reputation was dealt a heavy blow as an alleged instigator of murder.

[5] As her father-in-law Duke Frederick the Pious had died in 1478,[6] Anne took over custody and regency for her son Henry,[5][6] with the participation of secular and ecclesiastical councillors and the town council of the city of Lüneburg,[6] in a wise and prudent manner.

[11] After her regency ended in 1486, Anne lived in her town house in Celle, and for a time also in her dower Lüchow Castle, but she also kept in touch with her old homeland and often stayed in Dillenburg or at the spa in Bad Ems.

[5] A close relationship existed between Anne in Celle and her youngest brother Count John V. Based on the lively correspondence between them, it is even possible to reconstruct a trade exchange between the Duchy of Brunswick-Lüneburg and the County of Nassau-Siegen.

[12] An account from 1487 shows that on 13 July she was in Siegen, together with her brother John, to supervise the progress of the building activities of the Franciscan monastery he had founded there.