"Maybe she can take over for Lauren Ambrose on Sundays."
She might consider taking over for Diana Rigg, although the idea of her taking over for anybody seems far-fetched.
Julie made the decision to leave Broadway for Hollywood when she was still very young. She only returned, thirty years later, because her husband wanted to produce a musical and needed her name to get it off the ground. She did it for him, and it resulted in her voice being damaged. The surgery she elected to have to repair the damage had disastrous results. As noted above, she can no longer sing and her speaking voice is raspy. Plus, she is 82 years old.
I doubt she even wants to take on Broadway at this point.