These two stories -- Jesus raising Jairus' daughter and the healing of the woman who seeks to touch Jesus in the crowd -- are woven together in a single unit, in Matthew 9 and Mark 5 and here. They seem like odd stories to weave together, and there may be several reasons for the juxtaposition.
First, both stories confront things that are just beyond human ability to change. The woman has experienced a flow of blood for twelve years and Luke (the physician) makes clear that no human doctor was able to heal her, though she had exhausted all her resources on physicians, no one could help her. Her condition apparently caused her some distress physically, as she could tell immediately that she was healed. What's more, such a flow of blood would have made her perpetually ritually unclean according to the Jewish laws, so this is not only a medical but also a religious / spiritual / social problem for her.
The twelve year old girl's problem is more straightforward: she is dying. Her father, a man of standing among his neighbors, a leader within the Jewish faith, humbles himself because he has no power over his daughter's sickness. He is hopeless without Jesus. Anyone with any sense of empathy can imagine Jairus' impatience as Jesus pauses to deal with this woman whose condition is sad, tragic, but not immediately life-threatening. Then the dreaded messengers come: "Do not trouble the teacher any more." His daughter is dead. Hope is gone. There is no way back to joy.
Second, this entire narrative points to the authority of Jesus over situations that are beyond human control. Merely touching the fringe on Jesus' garment, even without his intention, brings healing to the woman. And death itself is redefined in his presence. (I love the certainty of the mourners -- probably a mixture of extended family and professionals hired for the purpose, all more than familiar with death -- in verse 53: "they laughed at [Jesus], knowing that she was dead.") Under Jesus' authority, death itself is redefined as a temporary thing. Jesus stands over even the most ironclad of institutions, things that we cannot imagine being altered or changed, and he does it not by supreme effort but simply by his presence.
This is why it is so critically important for Jesus' followers -- in that day and in this -- to remain close to him. Where our human understanding runs down to despair, Jesus brings life and hope. Where we are imprisoned, whether by human institutions or physical constraints or death itself, in the presence of Jesus there is freedom.
Joy is not an illusion. Jairus must have thought that all the brightness had just gone out of his world. One can imagine all the "if-only's" running through his mind: If only I had gone to Jesus earlier. If only I had carried my daughter with me so he could have touched her. If only she hadn't gotten sick. If only. But Jesus says, "Do not fear; only believe." Can we trust in the face of our own hopelessness? Jesus leads Jairus and his wife past the mourners, past the mockers, past those living in their certainty about the permanence of death, and into the house where this girl has woken up each day for twelve years. Jesus takes her lifeless hand, as one can imagine Jairus doing each morning. Jesus speaks the words Jairus has probably spoken each day to wake her up to new life and possibility: "Child, arise." In Jesus' presence, death itself has no sway, no permanence. She opens her eyes and gets out of bed. She is free from her deadly bondage to death, restored to life and relationship and joy.