This is serious although it sounds sort of joking...do you belive she hears your prayers? I mean, in order for her to hear all the prayers she would have to be omnipotent and omnipresent right?Well, not necessarily. I don't really know how it works, but I do know that, in virtue of being spirits in heaven, they are aware of our prayers. I say "aware" because, technically speaking, words like "seeing" and "hearing" are inaccurate. A soul without a body (and thus without eyes and ears) can neither "see", nor "hear." Really, these words just reflect an awareness that the saints have of our prayers.
There are various passages of Scripture that show that the angels are indeed aware of and respond to what happens to us on earth:
Psa 34:7 The angel of the LORD encamps around those who fear him, and delivers them.
Mt 18:10 "See that you do not despise one of these little ones; for I tell you that in heaven their angels always behold the face of my Father who is in heaven.
Lk 15:7-10 Just so, I tell you, there will be more joy in heaven over one sinner who repents than over ninety-nine righteous persons who need no repentance. 8 "Or what woman, having ten silver coins, if she loses one coin, does not light a lamp and sweep the house and seek diligently until she finds it? 9 And when she has found it, she calls together her friends and neighbors, saying, 'Rejoice with me, for I have found the coin which I had lost.' 10 Just so, I tell you, there is joy before the angels of God over one sinner who repents."
1 Cor 4:9 For I think that God has exhibited us apostles as last of all, like men sentenced to death; because we have become a spectacle to the world, to angels and to men.
Heb 12:1 Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight, and sin which clings so closely, and let us run with perseverance the race that is set before us [note: the image here is one of a round colloseum where the spectators of a race appear as a cloud surrounding the runners]
If they can "see" us all, then there's nothing to keep them from "hearing" us all either. I think the most striking evidence that the saints are aware of, or "hear" our prayers comes from the book of Revelation:
Rev 5:8 And when he had taken the scroll, the four living creatures and the twenty-four elders fell down before the Lamb, each holding a harp, and with golden bowls full of incense, which are the prayers of the saints;
Rev 8:3-4 And another angel came and stood at the altar with a golden censer; and he was given much incense to mingle with the prayers of all the saints upon the golden altar before the throne; 4 and the smoke of the incense rose with the prayers of the saints from the hand of the angel before God.
Angels are seen here taking our prayers, which rise up to heaven like incense (Psa 141:2), and presenting them to God. When a saint prays for us (which is also called "interceding for us") that is what he does. He brings to God the needs of his people expressed through prayer.
We also see intercession of the saints in the following passages:
Jer 15:1 Then the LORD said to me, "Though Moses and Samuel stood before me, yet my heart would not turn toward this people. Send them out of my sight, and let them go! [note: at the time of Jeremiah, Moses and Samuel were already dead].
Job 33:23-24 If there be for him an angel, a mediator, one of the thousand, to declare to man what is right for him; 24 and he is gracious to him, and says, 'Deliver him from going down into the Pit, I have found a ransom;
Rev 6:9-11 is another possible example.
All of this shows that the angels and saints in heaven are aware of our lives and our prayers and are interceding for us. Whether this is in virtue of their "omnisience" or "omnipresence" I do not know.
Perhaps they are aware of our prayers because, after physical death, the soul enters into a place and a state that is beyond our laws of physics, laws that govern space, and place, and time. Angels often just appear and then disappear. After Jesus's death and resurrection, he was able to do the same thing, even appearing in a room although the door was shut (cf. Jn 20:19).
Or, perhaps it is because the saints in heaven are not actually separated or shut off from the saints on earth. Catholics believe that the saints in heaven and the saints on earth make up one mystical Body of Christ. In grace, we are all connected to Christ. This is a no-brainer. But, in grace we are also connected to each other:
Rom 12:4-5 For as in one body we have many members, and all the members do not have the same function, 5 so we, though many, are one body in Christ, and individually members one of another.
1 Cor 12:13,26 For by one Spirit we were all baptized into one body--Jews or Greeks, slaves or free--and all were made to drink of one Spirit. 26 If one member suffers, all suffer together; if one member is honored, all rejoice together.
2 Cor 2:5 But if any one has caused pain, he has caused it not to me, but in some measure--not to put it too severely--to you all.
Eph 1:9-10 For he has made known to us in all wisdom and insight the mystery of his will, according to his purpose which he set forth in Christ 10 as a plan for the fulness of time, to unite all things in him, things in heaven and things on earth.
Eph 2:19-21 So then you are no longer strangers and sojourners, but you are fellow citizens with the saints and members of the household of God, 20 built upon the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone, 21 in whom the whole structure is joined together and grows into a holy temple in the Lord;
Eph 4:15-16,25 Rather, speaking the truth in love, we are to grow up in every way into him who is the head, into Christ, 16 from whom the whole body, joined and knit together by every joint with which it is supplied, when each part is working properly, makes bodily growth and upbuilds itself in love. 25 Therefore, putting away falsehood, let every one speak the truth with his neighbor, for we are members one of another.
Col 2:18-19 Let no one disqualify you, insisting on self-abasement and worship of angels, taking his stand on visions, puffed up without reason by his sensuous mind, 19 and not holding fast to the Head, from whom the whole body, nourished and knit together through its joints and ligaments, grows with a growth that is from God.
Heb 13:3 Remember those who are in prison, as though in prison with them; and those who are ill-treated, since you also are in the body.
So, by grace, we are connected to Christ and to each other, and together this connection makes up one Body of Christ. There is no reason why death should destroy this unity, especially since Jesus conquered death and because the saints in heaven are actually more alive than we'll ever be on earth. Is not God after all, "the God of Abraham, and the God of Isaac, and the God of Jacob'? He is not God of the dead, but of the living" (Mt 22:32). Thus, communication amongst all the members is maintained. As a result, I can ask a saint in heaven to pray for me just as much as I can ask a saint on earth, and a saint in heaven can intercede for me just as you can.
These are two possible reasons for why the saints are able to hear our prayers. But, to me, why they are able to hear our prayers is not as important as the fact that they can......and Scripture supports this saintly awareness.