There can be several things going on and this may require some investigation. It sounds like she is failing to poop in the yard when sent out for a good half hour. Then, in the home, the urge may be too strong and she has an accident. So we need to find out why she is no longer pooping in the yard. Perhaps there are noises that concern her and make her not feel safe to potty? Perhaps there are critters in the yard which distract her causing her to be too focused on sniffing and digging? It may be a good idea to get a flashlight and see from a distance what may be happening. You may need to see whether she poops or not during the half hour. If she does poop, and then she poops again the morning, then we may be dealing with a different problem.