Hi, my daughter Kacey is almost 2.5 years old.
Erika, Hi and welcome to the Toilet Teaching board.
When a child is sick they can regress, especially if they are still in the early stages of learning. I would suggest giving her a 3 to 5 days to fully recover before trying to get her to use the potty, go back to diapers. Then when she fully recovered start potty training over like you were from the beginning, you should she her progress to where she was before quickly. I hope that helps. Please keep us updated on your DD's progress.