I think you're doing better to keep her. She's in a bad area for a feral, and could be hit by a car or mauled by a dog or cat.
I think you should go with your plan and see how she does in a few weeks. But good cover in the run might help, and I'd check for eggs where you found her.
I think you should go with your plan and see how she does in a few weeks. But good cover in the run might help, and I'd check for eggs where you found her.