My H and I have the same workout schedule. He is early morning, and I do it during the baby's naptime. I would never ask to do it early morning because I don't ever want to stand in the way of his workout.

Does she have a good reason to want to work out in the morning for just one day? Or, is she just wanting to take the morning slot?

I would hope that my H and I could switch to solution mode, and say "OK, I'll just go earlier at 5am and you go at 6am. If you want to do this on a continual basis, maybe we can work out a schedule so that we share the earlier shift."

Would that work?

If she's just asking for one day, no biggie to be flexible and just skip a day... no?

Lucky