Tilly Fagan is the wife of Robert Fagan.
As one of the richest persons in the solar system, she is a known socialite and keeps very highly-placed company, such as Jules-Pierre Mao and his family; his daughter Clarissa Melpomene Mao grew up calling her "aunt Tilly".
Tilly is described as 'flighty' and she comes off as vapid and not offering much in the way of political or intellectual conversations. She puts on a front of friendly, chipperness, but Anna Volovodov can see she is, in fact, a deeply lonely woman. Sadly, she tries to get noticed and to get the attention of people around her, even though she has little to contribute.
She introduces Anna to the other religious leaders on the UNN vessel such as Hector Cortez, and Father Michel.
She helps guide Anna to The Thomas Prince's security station following the traumatic incident in the Slow Zone.
Due to her personal relationship with the Mao family, she is able to express honest blatant criticism of Jules-Pierre Mao without incurring wrath and resentment from Clarissa. This allows Clarissa to start to open up and come to terms with her conflicting emotions.