You said "This is what she usually does" so I assume she has some sort of formalized experience in house sitting and she probably does have some expectations. Honestly I can't imagine anybody sleeping on a couch with a blanket when there's empty beds feet away. If it were me I'd tell you I slept on the couch and then I'd go sleep in the bed, so better not to hire me for that one.
I've only hired what I guess you'd call Professional Housesitters, in that they have client lists and contracts and recommendations and all that stuff and are not personal friends of ours but here are my experiences. I'm actually more comfortable with that than close friends who might be tempted to go through things and then gossip.
Yes, they expect a bed. With clean sheets. If you leave out a second set of bedding they will wash what they used and remake the bed for you before they leave. I can't remember what the contracts actually say but there was places in there for the homeowner to indicate which bedroom and bathroom they should use.
It seems to be common in my experience to leave them food for a first meal and then a list of nearby grocery stores, delivery, and restaurants. They often in return leave food for you. I've had everything from an accounting of what they used from my freezer and pantry with it replaced, to a bowl of fruit, some cookies and a bottle of wine.
Everything single time I have to admit that they've left my house probably cleaner and better than how they entered it. That's nice.
The group I usually use are all students/work from their laptop types and a reliable high speed internet was absolutely required. They also wanted a good work space reserved for them like a desk or dedicated table space.
The contract also states whether or not they get use of our cars. The ladies we've had here have all had their own vehicles so that just gets crossed out.
I usually go through the house and collect papers and anything else I consider too private or confidential and we put it all in a suitcase up in our attic. I usually start that about the week before and make 3 or 4 sweeps through the house and by the time they get here there really isn't anything left that I wouldn't want them to see.