In 2006 Dolly was one of the Kennedy Center honorees for contributions to American culture. Here she is enthusiastically showing off her... contributions. Or ostensibly the medallion she was awarded.
She was 60 years old then, and she still looked great at the time. Next year she will be 80 years old. 
She was looking good.
There has been speculation for some years, at least online, that Dolly has had a reduction and wears a breastplate when she is in public. Cannot confirm the veracity of such claims, but no doubt weight becomes more difficult to carry when one gets older, and complications from surgeries are of course possible. No matter how wonderful the "amplifying" effect is.