So, for double yolk eggs (I'm having trouble tracking down the literature on it) I believe that chickens that regularly lay them have a higher rate of prolapse and other reproductive problems and issues. But it's not like there's anything to be done about it, the only way to stop it would be to basically give the bird chicken birth control to stop all laying (which some vets have done but it's prescription only and expensive and has its own side effects, it's used on pet doves and parrots sometimes).
So basically just keep an eye on your hen for other problems they may be more prone to.
So basically just keep an eye on your hen for other problems they may be more prone to.