By all means neither Peggy Rea, nor Sorrell Booke, were thin or skinny people. But, I’ve seen both on many other things, before & after “Dukes”.
We all know Sorrell wore a fat suit, as he wasn’t as obese as his character of Boss Hogg. Looking at Peggy in some other things, yes she was heavy…but she was no where near what her character of Lulu was on “Dukes”.
I’m thinking she wore a fat suit as well…to exaggerate her weight, just like Boss. Part of the show’s & Hazzard’s charm was everyone & everything was overly exaggerated. It was fun, entertaining, and created a place you truly wished existed.