My daughter has been potty trained for three months with some accidents. She was doing so well but the accidents have recently increased significantly. She's pooped in her panties two days in a row.
Toilet training is a lot of work for both the child and parents.
Remember that accidents will happen naturally, so try not to get too frustrated by them. Just like learning to tie her shoes, toilet training takes lots of practice to make perfect. Explain that her body makes poop everyday which needs to go into the toilet. It's also important to keep your daughter on a regular schedule. Having her sit on the toilet shortly after a meal helps.