Who is Servilia from Caesar's Women and what is their importance?

Servilia was a rich aristocrat who came from a well-respected Roman family. Married twice, Servilia's first husband was Brutus' father. Her second husband was a Roman Senator, though he is described as a man who was both handsome and frail. Servilia is described as a domineering, cruel, and ruthless woman.

Over the course of the novel, we also learn that Servilia had an affair with Caesar while she was married, and even bore him a child.... though she forced her husband to give the child his name.