How does Jennet Clouston react to David's question about the house?

From the text:

"That is the house of Shaws!" she cried. "Blood built it; blood stopped the building of it; blood shall bring it down. See here!" she cried again—"I spit upon the ground, and crack my thumb at it! Black be its fall! If ye see the laird, tell him what ye hear; tell him this makes the twelve hunner and nineteen time that Jennet Clouston has called down the curse on him and his house, byre and stable, man, guest, and master, wife, miss, or bairn—black, black be their fall!"