You need to ask “Why did God grant Mary so many graces?” to understand what he accomplished by doing that.
Mary is the Second Eve–the one whom God chose to be the Mother of the new humanity, redeemed in Christ, the Second Adam. As Eve was the mother of all humankind, but fell, bringing to all death, so Mary is the one who brought life to all mankind in her Son. When Mary said her fiat she knew she was accepting a mission not just the graces to live a perfect life. She needed those graces because of the high mission she was to fulfill–not because she deserved them more than anyone else. Although, by her faithfulness to God–her cooperation with his will she did gain graces because of that.
God grants special graces to individuals to fulfill his will in their lives. He chose many people down through history for special missions, Mary wasn’t the first. They all underwent great trials. Some were put to death. Are you ready for that?
What we need to remember is that along with many graces come many sorrows, trials and troubles. Jesus said, “To whom much is given much is required.” If you truly want all the graces Mary has, you have to be willing to suffer all she suffered. Are you ready for that? If not, you may want to rethink being jealous.
James and John asked Jesus to sit at his right and left in the Kingdom. He asked them, “Are you prepared to drink from the cup I must drink from?” In their arrogance and ignorance they said, “Yes.” So, he told them that they would indeed drink from the same cup–the cup of suffering and martyrdom. Are you willing to be a martyr or do you just want the glory? You cannot have the glory without the cross. First embrace the cross Christ gave you and then think about the graces you wish him to give you.