Under the nickname die Beständige ("the Resistant"), she was co-founder and the second head of the Académie des Loyales, one of the female counterparts of the Fruitbearing Society.

After his death, she took up regency for her young son Gustav Adolph, as specified in her husband's testament.

However, only three days later, her brother-in-law Adolf Frederick I deposed her as regent and guardian of her son and took up those rôles himself.

Nobody dared to participate in the private Calvinist services Eleonore Marie organized, and she was referred to hew window seat in Strelitz.

However, Adolf Frederick continued his court cases against her, and involved foreign powers into the matter.