Sim.

Nos livros, Cersei tem Margaery acusada de fornicação com Osney Kettleblack e uma grande variedade de outros supostos amantes. De o wiki aSoIaF :

Cersei accuses Margaery of adultery and treason, lining up an impressive, if untrue, array of conspirators and evidence by torturing the Blue Bard. After Cersei discounts accusing Loras Tyrell, Horas Redwyne, and Hobber Redwyne, Maergery is accused of having slept with:

• Osney Kettleblack
• Jalabhar Xho
• Bayard Norcross
• Ser Tallad the Tall
• Hugh Clifton
• Hamish the Harper
• Lambert Turnberry
• Mark Mullendore
• The Blue Bard

Margaery is arrested and imprisoned to await trial by the Faith at the Great Sept of Baelor. While in custody, Margaery confronts Cersei, revealing that she knows that Tommen's mother is behind the accusations and wants to remove the young queen from a position of influence, perhaps by arranging for her death. Later, one of Cersei's key witnesses, Osney Kettleblack, reveals her plots under torture, and Cersei soon finds herself sharing Margaery's plight under similar charges.

Para mais detalhes, veja Um banquete para os corvos , capítulo 39 .

Não

De acordo com o programa, ela não é acusada de mais nada; em vez disso, ela será julgada para descobrir se ela é culpada de qualquer outra coisa.

CERSEI: Her accommodations seem sufficient. What happens to her now?
SPARROW: Well she and her brother are both being held under fair suspicion. A trial will be held for each of them to determine if they are guilty of any acts that might constitute a violation of the tenants of the faith.
_{Game of Throne, Season 5 Episode 7, "The Gift"}

CERSEI: If one or both of them were to confess before the trial…
SPARROW: Then they will be at The Mother’s mercy.
CERSEI: What does The Mother’s mercy entail?
SPARROW: It depends on the situation. The acts themselves, the degree of contrition.
_{Game of Throne, Season 5 Episode 7, "The Gift"}

Mais tarde, quando Margaery está em sua cela, o High Sparrow a visita e eles têm a seguinte conversa:

HIGH SPARROW: It isn’t Ser Loras that brings me here. Your husband misses you dearly. The love between a man and wife is sacred. It reflects the love the gods have for all of us. But sin leads us away from the sacred. And only confession can purge sin.
MARGAERY: I have nothing to confess.
HIGH SPARROW: So you believe you are pure? Perfect? Wholly without sin?
MARGAERY: None of us are.
HIGH SPARROW: You have started down the path. But you have many miles to go..
_{Game of Thrones, Season 6 Episode 1, "The Red Woman"}

Então ela está comentando que ela não está totalmente livre de pecado e o Alto Pardal parece aceitar isso como ela começando no caminho para a redenção.

Nunca é totalmente declarado se ela confessa ou não, mas ela começa a acreditar, ou fingir, nos caminhos do Alto Pardal. Ela chega a convencer Tommen a se converter.

TOMMEN: What about Loras?
MARGAERY: I love my brother. I will always love my brother. His soul is pure and perfect. His sins don’t erase that purity, they only obscure it. He just needs to atone for them. We all do. Sooner or later, one way or another. The gods have a plan for us all.
_{Game of Thrones, Season 6 Episode 6, "Blood of My Blood"}

A citação acima não mostra exatamente que ela converteu Tommen, mas que ela agora está agindo nos caminhos da Fé. No entanto, mais tarde, no episódio em que Jaime vem parar a Rainha de sua caminhada de expiação, temos a seguinte cena. Não está claro se Margaery confessou alguma coisa para a caminhada ou se foi para mostrar o que acontece.

HIGH SPARROW: To die in the service of the gods would please each and every one of us. We yearn for it. But there is no call for it today. There will be no walk of atonement.
CAPTAIN: Order up!
HIGH SPARROW: Queen Margaery has already atoned for her sins by bringing another into the true light of the Seven. Together we announce a new age of harmony. A holy alliance between the Crown and the Faith.
WOMAN: Long live King Tommen and bless you, Queen Margaery!
TOMMEN: The crown and the faith are the twin pillars upon which the world rests. Together we will restore the Seven Kingdoms to glory.
_{Game of Thrones, Season 6 Episode 6, "Blood of My Blood"}