It's possible he just may have some idea what he's dealing with.
I mean, given the gossiping that appears to be going around the office about her, it would be hard for him to have not heard it.
And, that he does actually want something more than just being friends with benefits.
But is willing to use that as an opening wedge.
She really is working herself into an early grave.
At which time, of what use her accomplishments?
There must be more to life than your work.
There needs to be a demarcation between work and not-work.
Yes, when you get high up in management, sometimes it is necessary to be contacted outside of normal hours, but it should only be for true emergencies; of what use are subordinates if they cannot deal with most things that come up?
Just how frequently do true emergencies occur outside normal hours? If too frequent, hire additional staff to cover those hours and deal with it.
A firm that stays in the black only due to overworking it's employees, is not actually staying in the black; the turnover they will experience, the deterioration of their staff as a result of the overwork, these are true expenses that must be accounted for.
An employee who overworks voluntarily, who is not being asked to, is actually a bad employee, as they will be more likely to have a severe burnout that the others. And they are falsifying the actual staffing needs of the firm; when they leave, that will be discovered, when it takes more staff to do the job they were doing, and it won't have been budgeted for. And they are more likely to ask others to overwork, which again falsifies the true staffing needs. Most advanced countries have legal limits to the number of hours you can be asked to work in a week; true staffing levels will reflect what that necessitates.
She really needs to realize that her job is just that, a job.
No matter how passionate she is about it, it still needs to be restricted in how much it impacts her life.
There needs to be more reason for living than your work.
What good is success in your job, if it doesn't positively impact your life outside of work?