She supported the poor financially, handled taxes, welcomed Jewish and Muslim refugees, attempted to end conflict between noble houses, and corresponded directly with the Avignon-based Antipope Benedict XIII (himself Aragonese) to suggest bans toward laws and practices she saw as unjust.

[1] As Lope's first marriage to Violant of Aragon produced no children, Maria was formally named her father's sole heir shortly after her birth.

For this reason, she soon attracted the attention of Peter IV the Ceremonious, King of Aragon, who was eager to arrange a marriage for his younger son, Martin.

Maria first shows up in Queen Eleanor's account books as early as 1362, suggesting that she moved to court around age four or five – several years earlier than the terms of her engagement originally stipulated.

Although there is little information available about her upbringing at court, her education was in all likelihood a thorough one, given surviving evidence of her writing, the collection of books she possessed, and how quickly she took over the administration of her estates upon coming of age.

[6] She and her husband enjoyed considerable royal favor; in the fifteen years following Maria and Martin's marriage, King Peter continued to bestow offices and lands upon his younger son.

[14] María de Luna was a proponent of the so-called Devotio Moderna, a type of Christian worship that rose to prominence in the later Middle Ages which emphasized oral prayer and intense affective meditation upon the words and deeds of Jesus.

Joan Eiximenio was her personal confessor, and he translated Arbor vitae crucifixus ("the book of life of the crucified") of Ubertino de Calae (1259–1330) into Catalan.

María de Luna associated with the Franciscan friars and donated money for their monastic foundation of the Holy Spirit (the Monasterio del Santo Espíritu).

Compared to those surviving for other households of similar rank in this period, the accounts of Maria de Luna in "Food in the Accounts of a Travelling lady: Maria de Luna, queen of Aragon, in 1403" contain more detail, describing specific dishes cooked for the queen's table, the food consumption per person, the weight of the animals used for meat, and the amounts of wheat used to make a certain quantity of bread.

Customs were distinct in every royal household, and Maria de Luna's was defined by "her close relationship with the mendicant orders and with charity, but also through the attention she paid to medical advice, given her fragile health."

[21] María once more swam against the tide of the jurats' public opinion in 1403, when her husband Martin passed a law that would force Jews in the kingdom to wear large badges of both yellow and red.

When María realized that Jacob Façan, a Jew who had provided much monetary assistance to the throne, was being investigated for unfaithfulness to the Catholic religion, she intervened to protect him.

In an attempt to mitigate the effects of inquisitions, she originally tried to use a bargaining tactic, recognizing that some Jews might indeed deserve punishment, but rather trying to regulate the forms of investigation to which they were subject.

In 1402, she sought to end the exploitation of the remença, the rural Catalonian peasantry by their aristocratic overlords, decrying such practices as "bad habits" (malos usos).

As Eiximenis explained in the dedicatory preface to his work: Most High Lady, many times your great Ladyship has encouraged me, for the improvement of your spiritual life, to prepare as you request some little book from which you might derive some guidance or light to better guard you from any offence to God, and that you might most aptly enjoy in all virtue, and better please God: for which, Most High Lady, I—wishing to satisfy your pious intentions, and for the sound increase of your devotion—have assembled the following book.

For Eiximenis, "feminine space was constructed around and limited to the home, the family, and the body",[29] which meant that instead of characterizing her as queen-lieutenant and governor, he placed her in a secondary, dependent role.

Queens, Eiximenis believed, have a distinct and secondary status because they are female: [The queen] owes it to her husband at all times to conserve the peace in the kingdom and ensure swift, righteous, and clear justice to their peoples, and not under any circumstances act as a tyrant, but rather to show herself likable and dear to her people, and take counsel from a small group chosen from among them, and fearing God, and eschewing greed, and who are committed to the common good and not their own affairs.

Praying alone in a private room or chapel, at night or early in the morning, served not only to underline the humility and authenticity of devotion, but quite simply to ensure that she would not be interrupted.

"[31] Nuria Silleras-Fernandez, in Chariots of Ladies, suggests that the Scala Dei, and Maria de Luna's personal relationship with Eiximenis more generally, substantially shaped her queenship and subsequent reputation.

Silleras-Fernandez argues that "Eiximenis inspired Maria to cultivate became the kernel of her royal persona, or, as she preferred to call it in her letters, her 'queenly dignity' (dignitat reginal)."