I would with my son, absolutely. I know him, and he'd keep to whatever I laid out in terms of guidelines. Only you know your DD. How independent is she? Does she follow the rules when you're not around? My son does. My DD? I'd have to split my time from work for my own peace of mind----a break for lunch at the very least. If there were spaces I could check in on her, maybe those as well. I'd be concerned about MY DD because she's not as cautious as DS. And, she thinks she's smarter than anyone else. Ugh.
But, DS? I could drop him at a mall, then check in at lunch. Have lunch with him, then back to the hotel for an afternoon of room service and movies. NBD. Could you trust DD to do something like this?
All of it depends on who your DD is, her interests and level of maturity. It could be a total game changer, to trust her like this. I don't know the city. That, of course, also plays a part in the decision making here. For example, in DC, I could send DS downtown to the Spy Museum and the Portrait Gallery, meet up at Clyde's for lunch, then take him back to the hotel. He could totally manage that. For DD, it would look more like a trip to Mazza Gallery, (ha!) lunch at Clyde's, then back to the hotel. But, boy, I'd be thinking about her constantly.
Whether it's a day in the hotel or out and about in the city, you should plan her day. Pool, lunch, workout, shop online or plan a day with you in the city with the concierge,...there's lots of stuff to keep her busy for the day, while you are at work. A big night out for a fancy, grown up dinner with Dad sounds cool, too! Especially if she has to spend part of the day picking out an outfit from the local mall while you're working.
Only you know who she is and what you're comfortable with, OP. It could work.