The gas giants would have to be captured planets (otherwise they would have been destroyed when the star went nova and turned into a red dwarf), although that isn't outside the realm of possibility.
This actually helps your setup - if the captured planets are in different orbital planes than the double-planet and each other, it would be more difficult for any of them to be detected...
--
Rob Kelk
"Governments have no right to question the loyalty of those who oppose
them. Adversaries remain citizens of the same state, common subjects of
the same sovereign, servants of the same law."
- Michael Ignatieff, addressing Stanford University in 2012
This actually helps your setup - if the captured planets are in different orbital planes than the double-planet and each other, it would be more difficult for any of them to be detected...
--
Rob Kelk
"Governments have no right to question the loyalty of those who oppose
them. Adversaries remain citizens of the same state, common subjects of
the same sovereign, servants of the same law."
- Michael Ignatieff, addressing Stanford University in 2012