Sophie and her grandmother were seated on the porch stairs in a tearful hug when the young docent dashed across the lawn, his eyes shining with hope and disbelief.
Through her tears, Sophie nodded, standing. She did not know the young man's face, but as they embraced, she could feel the power of the blood coursing through is veins…the blood she now understood they shared.
When Langdon walked across the lawn to join them, Sophie could not imagine that only yesterday she had felt so alone in the world. And now, somehow, in this foreign place, in the company of three people she barely knew, she felt at last that she was home. (104.108-111)
So, the whole "power of the blood" thing is a bit much, but this is a huge moment for Sophie. Even after the devastating death of the only family she'd ever known, she can finally find peace with the family she's finally rediscovered.