Who is Eleanor 'Nell' de Montfort, Countess of Liecester from Falls the Shadow and what is their importance?

Eleanor (Nell) de Montfort is Simon de Montfort's wife. She meets Simon de Montfort while still married to her first husband, and they meet again after his death. That meeting led to regular correspondence that quickly developed a relationship between the two. Knowing her brother would never allow them to marry, Nell lied to her brother and told him she was pregnant. This lie is later responsible for Henry's banishment of the couple from court.

Nell is described as a strong woman, who for the most part, raises her six children on her own. Her husband is often away, and she supports him without question. After Simon's death, Nell is devastated, but she finds happiness in her children.