That is what the OP is asking. I think. Hard to know.
With an ADA request, as you know of course, she meeds to make a request for a specific accommodation. That is what the OP is asking here in “figuring out what to ask for.”
And if it comes to a specific ADA accommodation, which I doubt it will, the OP should work woth her HR department first before getting all tangled with with her supervisor. Although,sure, I can see mentionng this accomodatin to her boss so he is not blindsided as in “Hey, my Dr. has made a recomendation for my health and I am talking to HR about it.”