Familial connections are actually fairly common in the NFL, some that easily come to mind are the Manning brothers, Peyton and Eli. Then you have the Barbers, Ronde and Tiki, or another set of quarterbacks in David and Derek Carr.
But what isn't quite as common is when these families actually get to play together on a team. Patriots TE Rob Gronkowski played with his older brother Dan briefly in New England in 2011, but nothing really came out of it. QB Carson Palmer played with his brother Jordan in Cincinnati back in 2010, but only Carson got to play of course.