Do Mary and the other saints know what we are praying for before we ask them? Jesus explains that God knows what we need before we pray:

Do not be like them, for your Father knows what you need before you ask him.
—Matthew 6:8 (NIV)

According to Catholicism, does the same apply for the saints? Do they know what we need before we ask them? Or do we have to actually ask them so that they are able to intercede on our behalf?
Do Mary and the other saints know what we are praying for before we ask them?

St. Thomas Aquinas say yes.


  Although the saints, after this life, know what happens here below, we must not believe that they grieve through knowing the woes of those whom they loved in this world: for they are so filled with heavenly joy, that sorrow finds no place in them. Wherefore if after death they know the woes of their friends, their grief is forestalled by their removal from this world before their woes occur. Perhaps, however, the non-glorified souls would grieve somewhat, if they were aware of the distress of their dear ones: and since the soul of Josias was not glorified as soon as it went out from his body, it is in this respect that Augustine uses this argument to show that the souls of the dead have no knowledge of the deeds of the living. 
  
  The souls of the saints have their will fully conformed to the Divine will even as regards the things willed. and consequently, although they retain the love of charity towards their neighbor, they do not succor him otherwise than they see to be in conformity with the disposition of Divine justice. Nevertheless, it is to be believed that they help their neighbor very much by interceding for him to God. 
  
  Although it does not follow that those who see the Word see all things in the Word, they see those things that pertain to the perfection of their happiness, as stated above. 
  
  God alone of Himself knows the thoughts of the heart: yet others know them, in so far as these are revealed to them, either by their vision of the Word or by any other means. - Question 72. Prayers with regard to the saints in heaven