This Bible contradiction is from the Skeptic's Annotated Bible.
She was already dead.
Matthew 9:18 View context
While he spake these things unto them, behold, there came a certain ruler, and worshipped him, saying, My daughter is even now dead: but come and lay thy hand upon her, and she shall live.
She was still alive.
Mark 5:22-23 View context
And, behold, there cometh one of the rulers of the synagogue, Jairus by name; and when he saw him, he fell at his feet,
And besought him greatly, saying, My little daughter lieth at the point of death: [I pray thee], come and lay thy hands on her, that she may be healed; and she shall live.
Luke 8:41-42 View context
And, behold, there came a man named Jairus, and he was a ruler of the synagogue: and he fell down at Jesus' feet, and besought him that he would come into his house:
For he had one only daughter, about twelve years of age, and she lay a dying. But as he went the people thronged him.