If I only paid cleaners $50, if not expect my house to be very clean. Maybe just some surface clean up like pick up stuff. Like if you buy a meal for $5, you’d not expect gourmet meal. You want gourmet, you pay 4 times more.
Yes she can stay longer but no one will work more than 2 hours for 50 bucks.
If you don’t like her, fire her. Find a cleaner through reputable company. But then of course you’ll pay more. You get what you pay for. Of course you deserve good things. But good things cost good money.