Margaret, queen of Scotland, was descended from the English kings by her father and from the Caesars by her mother. Like the prudent woman, mentioned in the Epistle, she was made still more illustrious by the practice of Christian virtues.
Filled with the fear of God (Introit), she subjected herself to fearful mortifications and by her example she brought the King, her husband, to a better life and her subjects to more Christian morals. She brought up her eight children with such piety that several of them led a life of high perfection. Nothing, however, was more admirable in her than her ardent charity towards her neighbour (Collect). She was called the mother of orphans and the treasurer of the poor of Jesus Christ. Such was the price at which she bought the precious pearl of the Kingdom of Heaven (Gospel).
Purified by six months of bodily suffering, she gave up her soul to God in 1093 at Edinburgh. The holiness of her life and numerous miracles wrought after her death have made her worship celebrated in the whole world. She was chosen by Clement X as patron of the Scottish nation over which she had reigned for thirty years.
Let us admire the work of the Holy Ghost in the soul of the holy queen whom He chose for the furtherance of Christ's Kingdom in Scotland and let us invoke her for the return of Scotland to Roman unity.
Cognovi, Domine, quia aequitas judicia tua, et in veritate tua humiliasti me: confige timore tuo carnes meas, a mandatis tuis timui. * Beati immaculati in via, qui ambulant in lege Domini.
I know, O Lord, that Thy judgements are equity, and in Thy truth Thou hast humbled me: pierce Thou my flesh with Thy fear, I am afraid of Thy judgements. * Blessed are the undefiled in the way, who walk in the law of the Lord.
(Psalm 118:75 and 120:1 from the Introit of Mass).
Deus, qui beatam Margaritam reginam eximia in pauperes caritate mirabilem effecisti: da; ut ejus intercessione et exemplo, tua in cordibus nostris caritas jugiter augeatur.
O God, who didst imbue the blessed queen Margaret with a spirit of singular charity towards the poor: grant that, through her prayers and example, Thy love may ever grow in our hearts.
From the Catholic Encyclopaedia: http://www.newadvent.org/cathen/09655c.htm