Nope, it's not her.

In case you were wondering, Curtains' brass-tacks producer Carmen Bernstein is NOT inspired by Fran Weissler. Debra Monk says:

"Everyone thinks Carmen is based on Fran Weissler, but Peter based my character on women he knew years ago. After all, the show is set in the 1950s... I really get all my information from what Peter and Rupert Holmes gave me. And I really like Fran."