Do Luke 1:48 and Luke 11:27-28 contradict each other? I have been replaying Luke 1:48 and Luke 11:27-28 in my mind. Something doesn't make sense here. Luke 1:48 is the part of Mary's song where Mary announces that all successive generations will call her blessed because of her son Jesus. Then, in Luke 11:27-28, when Jesus is a grown man in his ministry, a woman tells him that his mother is blessed for carrying him in the womb and nursing him, which ironically seems to allude to what Mary says earlier, but Jesus replies, "Blessed rather are those who hear the word of God and obey it." Apparently, Jesus is not concerned with his own pedigree, and if that is the case, does this mean that he rejects Mary's happiness? What's going on here?
Jesus' answer emphasizes what is more important. It is more important that a person hear the word of God and obey it than to be chosen by God for some special task. Not everyone will be chosen for a special position, but anyone can choose to obey God.

Jesus puts things regarding (his own) family into perspective: they are not as important as seeking the kingdom of God. When his family shows up, seemingly to talk some sense into him, Jesus tells the crowd:


  Matthew 12:50 (NASB) (also Mk 3:35)
  "For whoever does the will of My Father who is in heaven, he is My brother and sister and mother."


Regarding familial relationships and the call of God, he says:


  Luke 12:51,53 (NASB)
  "Do you suppose that I came to grant peace on earth? I tell you, no, but rather division; ... They will be divided, father against son and son against father, ..."


Nothing is more important than responding to God's call.

I don't think it's necessary to conclude that Jesus rejects his mother's happiness or her elevated position. He only tells the rest of us: don't wish you were her; instead, obey God.