I'm a night owl as well, and I definitely think I'd get less out of a morning appointment.

I also wouldn't want to have to have an entire workday after my session. I'm often emotionally exhausted and have a lot of intense feelings after a session.
I usually go back to work, but it's 6 or 7pm, so my boss has usually gone home by that point and even though a few people are all around it's not really the same social expectations. My coworkers have kind of picked up on the fact that I want to be given space and left alone after therapy.

You said she didn't propose something better... Have you asked her directly if it would be possible to switch to a later time?