Dolly Parton is set to make a guest appearance in the final season of Netflix comedy Grace and Frankie.The show, which debuted in 2015, reunites Jane Fonda and Lily Tomlin, who previously starred together alongside Parton in classic 1980 comedy film 9 To 5.In the show, the veteran actresses play longtime rivals who form an unlikely bond when their respective husbands, played by Martin Sheen and Sam Waterston, reveal that they are gay and planning to marry one another.Grace and Frankie was