tell his family that he foud Beauty dead in the hills? Instead of just saying nothing, wouldn't it have made more sense to just simply inform his family that Beauty was disembowled. The Carters would've known sooner what danger they were in. Sure it wouldn't have helped them, but it would've been better than keeping them in the dark until the last minute.
I'd have voted against telling them until I had to. They were all extremely brittle people, and not having two of their protectors around when they were already so stressed would have just made everything worse until it got worse. And with the protector point, especially, you don't want to tell them the thing keeping them safe just had catastrophic failure.
I agree, it was the nineteen seventies and Bobby didn't want to worry the women with disturbing information that they could do very little with. He was waiting for the men to return.