From YOUCAT, fact 147:
147: Why does Mary have such a preeminent place in the communion of saints?
Mary is the Mother of God. She was united with Jesus on earth as no other human being was or could be – in an intimacy that does not cease in heaven. Mary is the Queen of Heaven, and in her motherhood she is quite close to us.
Because she committed herself, body and soul, to a divine yet dangerous undertaking, Mary was taken up body and soul into heaven. Anyone who lives and believes as Mary did will get to heaven.