Unless you live in a rather humid area, I suspect you will be hard pressed to keep the eggs from drying out too much in a screen top aquarium. If you don't decide to go buy an incubator (the $40 Styrofoam chicken incubators at a farm store can work passably) I would cover as much of the top as you can without fire hazard with plastic or glass. Perhaps you can fill the end of the tank she isn't in with damp sphagnum moss (from a garden store) and spray it periodically with warm water. Also keep a water dish where she can reach it without leaving the eggs. I'm not sure if she will use it but I've heard a rumor that they might drink and pass fluids to help with dry eggs. I don't know if this is true but if nothing else it will help humidify the air and stabilize the temperature. You don't want to spray the eggs directly except for emergency dehydration and certainly don't want water running under them but if you can get the cage up close to 100% humidity that would be great.
I think you would want the temperature at her end to be around 86 - 88 deg F. If you do place heat directly under them it must be controlled carefully so as not to get too hot. I would think one of those proportional thermostats would be better than a simple on off to avoid too much temperature cycling. Maybe best not to have heat directly under them if it wasn't already there when she decided to lay. Maybe with a hot spot near by she can stretch out into it when she wants to raise the temp. Also maybe you could insulate around the outside of the tank, all the way around and top and bottom (but away from lamps etc.) to keep the air temperature up so it's not just surface heat. It would also help with privacy and keeping her calm. Mine threw out a good egg the first few days and I think it was because I was stressing her out looking too much. I think they are tougher than we think but I still believe you have a challenge to materially incubate eggs in a screen top aquarium. Maybe if you live in a warm costal area or are willing to turn her room into one but I know it would be extremely difficult where I live. Don’t give up on the eggs though as some pretty nasty looking ones have been known to hatch.
Also, how much fat does she have? Some pythons raise the temp by shivering and I think this would be hard on a skinny female (I'm not sure if ball pythons do this anyway though). I wouldn't think you would want to try to feed her while incubating though but if you do take the eggs then start feeding small meals and work up to get the weight back on.