What would you do? Driven manager's driving her people to burnout

Periodically, we ask three HR pros how they’d handle a difficult situation at work. Today’s problem: A workaholic manager’s staff longs for a little work/life balance.
The Scene
“We’ve got to find a way to rein in Carly,” said employee David Henderson. “She’s just too intense.”
David was in HR manager Brad Hess’s office, pacing back and forth.
“What’s the problem, exactly?” asked Brad.
David took a seat opposite Brad. “You know Carly’s my manager, and for the most part I like working for her – she gives good feedback and she has a good sense of humor.
“But she’s so driven – and she expects everybody to be as chained to the job as she is. It’s just not possible.”
“How do you mean?” asked Brad.
“Well, she’s the first one in and the last one to leave every day,” David said. “And she works almost as hard on the weekends. I’ve been working my tail off just to keep up, and I know I’m not the only one.
“Most of us in Carly’s department have kids and families,” he continued. “You know Carly’s a bit older and her kids are grown up.
“What I’m trying to say is just because Carly’s life revolves around work shouldn’t mean that our lives have to.”
Brad frowned. “Carly’s one of our top managers,” he said. “Do you really think it’s appropriate to tell her to stop working hard?”
“Look, you know we’re all committed to being successful here, but Carly needs to understand people have lives outside of the office,” said David.
“And between you and me,” he added, “I’ve heard that if things don’t change soon, some staffers may jump ship once the economy gets a bit better.”
If you were Brad, what would you do next?
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What your peers had to say
A  senior HR consultant in Virginia
What he’d do: I’d meet with Carly to let her know her employees are feeling pressured to keep up with her and her driven workplace personality.
Reason: Being upfront and transparent is the best way to tackle this situation.
Plus, it’s important to make sure that Carly and her staff are doing their work effectively. Managers and employees can work 12 hours a day, but at some point they start to be less productive than if they were working a solid eight hours.
An HR manager in Iowa
What she’d do: I might ask Carly in passing if there’s a way she could delegate some of the work she’s doing to another manager. But overall, I don’t think I’d do anything.
Reason: Who wouldn’t love to have a manager like Carly who gives her all for her company?
That’s the work ethic you want in an employee or manager, for the most part.
At the same time, I hear what David is saying, and you obviously want to avoid staffer burnout.
Asking Carly if she could delegate something might ease her workload and, subsequently, her staffers’.
An HR director in New Mexico
What she’d do: I’d speak with Carly, focusing on how the lack of work-life balance is affecting her employees’ families.
Specifically, I’d say something like, “How would you have felt if you couldn’t have seen your children very often when they were younger because you were working?”
Reason: It sounds like Carly is so focused on her work that she’s forgetting to also check in with her employees.
Relating employees’ experiences to Carly’s own from the past should hit home.