A Feast for Crows
Septa Moelle is escorted by six of the High Sparrow's knights when she comes before the Iron Throne to discuss the causes of Queen Margaery Tyrell's arrest. She explains that Margaery and her ladies cannot be released until their innocence has been proven, and reveals that she examined Margaery herself, and found the girl's maidenhead to no longer be intact.
A Dance with Dragons
Moelle is one of the septas who visit Cersei Lannister regularly. Cersei is awakened often with a demand of a confession. Moelle tells her it is her sins which are keeping her sleepless. She is present when Cersei declares she is ready to confess, and escorts her to the High Sparrow. Moelle is later amongst the septas who escort Ser Kevan Lannister to Cersei's cell.
Moelle, together with Septas Unella and Scolera, are part of the escort for Cersei as she completes her walk of atonement through the streets of King's Landing. Moelle explains Cersei must walk it barefoot.
Quotes by Moelle
A sweet face oft hides a sinner's heart.—Moelle to Cersei Lannister
Only the innocent know the peace of untroubled sleep. Confess your sins, and you will sleep like a newborn babe.—Moelle to Cersei Lannister
Quotes about Moelle
This one still has her maidenhead, I'll wager, though by now it's hard and stiff as boiled leather.—thoughts of Cersei Lannister