Did the Blessed Virgin practice self-denial?

Not in the way we understand it. We ourselves have to separate from creatures and from our egos, we have to abnegate our inclinations. But Our Lady is carried away by the splendor of the truth that radiates within her; driven by love, she gives herself, she would suffer not to give herself. Is she able to hold back, to hesitate? Obviously not. To believe or suspect it would be blasphemy.

Better than any human creature, Mary knows that the creature belongs to her Creator. And the Humanity she possesses within herself, and later cradles in her arms, finds its purpose only in the great sacrifice of Calvary. 

So not only does she want to give herself, she wants to give herself unreservedly to share the fate of this Humanity of the Redeemer, of the Lamb who will bear the sins of the world by immolating himself on the Cross. This is how she practices renunciation.

Dom Romain Banquet, First Abbot and founder of Saint Benedict of En Calcat Abbey

Retreat on the interior life given at the Saint Scholastica Abbey in Dourgne, November 1911.