Didn’t the Hinckley family know the Bushes?
Yes, they did.
From what I can tell, Hinckley’s parents had dinner with GHW Bush the night before on March 29th, 1981.
Bush Angle to Reagan Shooting Still Unresolved as Hinckley Walks
A Story I Had to Leave Out of My Book
RUSS BAKER 08/16/16
https://whowhatwhy.org/politics/government-integrity/bush-angle-reagan-shooting-still-unresolved-hinckley-walks/
Bush Killing Reagan: The Bush-Hinckley Conspiracy Bill O’Reilly Won’t Tell About
by Niles Mercado
https://www.amazon.com/Bush-Killing-Reagan-Bush-Hinckley-Conspiracy/dp/1519681933
THE BIZARRE CONNECTION BETWEEN JOHN HINCKLEY JR AND THE BUSH FAMILY
https://www.grunge.com/1100365/the-bizarre-connection-between-john-hinckley-jr-and-the-bush-family/