That seems very reasonable. As well as our own rental I look after one for someone else and although you say that she doesn’t have deal with issues, there’s a lot more to ‘cleaning’ than cleaning!
For example, does she have to buy her own cleaning supplies? Consumables such as soap, shampoo, loo paper etc? Does she clean the windows? The oven? Does she have extras like shower curtains, bathmats, throw pillow covers, etc. to launder? Does she iron? Does she change lightbulbs, AC filters and do general simple maintenance? Is there outside work such as sweeping pathways, the balcony etc? Does she keep the house manual updated? (It’s okay, I don’t expect you to answer all these!)
But it takes me four hours to do a turnover which includes buying supplies and laundry. (Also the house tour, availability during the stay etc. but that’s not relevant in your case).
To prepare a place for Airbnb guests is much more than ‘cleaning’.