As a child, Nanny was influenced by other slave leaders and maroons. She and her brothers, Accompong, Cudjoe, Johnny and Quao ran away from their plantation and hid in the Blue Mountains area of northern Saint Thomas Parish. While in hiding, they split up to organize more Maroon communities across Jamaica: Cudjoe went to Saint James Parish and organized a village, which was later named Cudjoe Town; Accompong settled in Saint Elizabeth Parish, in a community known as Accompong Town; Nanny and Quao founded communities in Portland Parish. She was married to a Maroon named Adou, but had no children.

Nanny and her brothers became folk heroes. The most famous of her brothers, Cudjoe, went on to lead several slave rebellions in Jamaica with the aid of her other brothers.

By 1720, Nanny and Quao had settled and controlled an area in the Blue Mountains. It was given the name Nanny Town, and consisted of the 500 acres (2.4 km²) of land granted to the runaway slaves. Nanny Town had a strategic location as it overlooked Stony River via a 900 foot (270 m) ridge making a surprise attack by the British practically impossible. The Maroons at Nanny Town also organized look-outs for such an attack as well as designated warriors who could be summoned by the sound of a horn called an Abeng.

Maroons at Nanny Town, and similar communities survived by sending traders to the nearby market towns to exchange food for weapons and cloth. The community raised animals, hunted, and grew crops, and was organized very much like a typical Ashanti tribe in Africa. The Maroons were also known for raiding plantations for weapons and food, burning the plantations, and leading slaves back to their communities.

Nanny was very adept at organizing plans to free slaves. For over 30 years, Nanny freed more than 800 slaves, and helped them to resettle in the Maroon community.