Sorry Marty, I am going have to say I have dismissed your WAG. Even if it goes against the idea of brainstorming
Let's review what we know.
Bridget is Bridget Bellvue, the window of her deceased husband Arnold Belvue.
George is George Alfred. A senior detective in the Police Department.
You could say that George is Bridget's brother, as that is what I'm taking you as saying, but here is the initial timeline of George being introduce to us:
Chapter 20 Gonzales and George meet to talk about how Gonzales' investigation is going.
Chapter 27 George and an unknown male pull up in the SeaWitch after a smuggling operation. George comes into the kitchen but the other male isn't mentioned again. Bridget 'kisses' him on his departure.
Chapter 30 Bridget kisses him again.
Okay so you might be saying well there is no mention of what kind of kiss it was. Was it a brotherly kiss, was it a friendly kiss, was it a two lip locked tonsil massaging kiss?
Chapter 31 Bridget and George take the SeaWitch to the Bahamas to meet with Sanchez (the first time we meet him) at the Atlantis hotel to arrange for the first attempt to kill Trevor while in the Suez Canal.
Chapter 32 Bridget and George finish up their meeting with Sanchez. Then this comment is made:
Okay, that is where I disagree with you. Bridget and George are longtime lover's. The narrator cannot lie . This means the previous kisses that could be debated are obviously made in affection, not a family greeting.
You could go and say that they are a sexually involved brother and sister, but sorry, that is just too Deliverance for me. I don't think CJ would have a sexual relationship between a brother and sister.
So there is why I don't think that George is Bridget's oft not mentioned brother. I would be more inclined to believe that the other man in chapter 27 may have been, or the boat marina owner possibly?
Just my thoughts