This sort of thing was influenced by the "Head and Shoulders" from c. 1970, with Penny and Farrah Fawcett and Penny of course playing a policewoman herself later on in a film or something like that...

Now, admittedly, Penny Marshall would have been a real bad ass policewoman for sure (given she's no lightweight herself, based on her performance from the first few Battle Of The Network Stars during 1976-77).

Only major downside would have been that the iconic Farrah poster would not exist at all, since Penny wouldn't be able to pull out that Farrah look.

Could have you imagined Penny Marshall as a Charlie's Angel?

Maybe had Kate Jackson not been hired and 'L&S' hadn't existed, I could imagine Miss Marshall playing 'the smart one'. I definitely think she'd have added an extra comedic edge to the dialogue- especially with Bosley. However; I'm not sure she'd have been so happy to constantly cocoon herself in towels while the others were in the tiniest of bikinis.

I see old episodes. She didn't look fat to me. She looked good !

Sorry to be a downer, but I really don't think it would've worked. Penny is a naturally funny woman and I don't think her personality would have fit with the tone of the show. Plus she wasn't glamorous enough. I know Kate downplayed her looks but still...