I don't get it. Charlene is Albert's wife, the considerably younger mother of his heirs and presumably being instructed in the workings of the Principality. We have absolutely no reason to suppose otherwise. Princess Caroline has a long history of charity and cultural work and this makes her more suitable to run a country how? She is older, that's it. Hey, she may even predecease her brother!
It has always been a fascination of mine the way that Monaco became all about Grace when HSH Prince Rainier married her and, since her death, all about her fabulous daughter Caroline. Neither of them had anything to recommend them from any other person of note, other than their beauty. AKA, Hollywood strikes again!
For years as Albert failed to marry, Caroline was de facto First Lady and heir presumptive and her children were heirs by default. But they are all pretty people and it was presumed that when the not so slim Albert finally popped his clogs, Caroline (if she hadn't predeceased her younger brother) would become Her Serene Highness The Sovereign Princess of Monaco, her children, its heirs.
But, Albert did marry and Albert does have legal heirs, two of them and so Princess Caroline is in the same situation as Princess Margaret, Prince Andrew and Prince Harry, basically redundant, barring the death of their sibling and his/her heirs. But the Monaco Dream Machine is still running and it says Caroline will rule. I think even the word "Regent" stuck in her fans throats, but they'd take it if that was as close as she got. But now, not only is she not destined to rule, she is not destined to be Regent either.
So unless something disastrous happens and wipes out the entire Regent family, Princess Caroline and her children's destinies lie elsewhere. And I know that's not the Hollywood way but HSH Charlene will be Regent if worst comes to worst.
But I'm betting that a healthier and happier Prince Albert will continue to thrive as a loving husband and father way past is his heir's 18th birthday.