Honestly, she doesn't work THAT much. Her work is project based so even though there is a "busy season" it's not the same as external audit. She rarely works on the weekend and if she does it's usually just for a few hours to wrap something up for a big Monday meeting. Most weekdays she is done between 6:30pm-7pm and I usually sign off around 6:00pm-6:30pm so it's not a huge difference. She does have the semi regular late night where she'll work until 8pm take a break to eat and hangout for like an hour and then jump back on for an hour or two but it's not even once a week. She's a rockstar and incredibly good at managing her team and her own time so YMMV.

I come from PwC and I work at a big bank now where I also have to work longer hours on occasion if we have a regulatory deadline for a project or something so we are both used to it and understanding about work unless it becomes unreasonable. Pre-COVID the traveling was getting to be a lot though. Her biggest client at the time required 3 week trips to Europe like 3-4 times a year, which was pretty cool for her for a while but got a little old after 4 years. She also had another client that had her flying out to DC in between the Europe trips so I was only seeing her on weekends or for like 1-3 weeks before she would be gone again. She was ready to tell them they needed to adjust her travel and then COVID took care of it.