It seems a little early for the terrible twos but who knows. She seems to be rebelling at something.
What I would do is go back to page 1 and start over. Pretend she's never been potty trained and start from the beginning. I'm sure you let her know how unhappy you are?
Are there other "new" behaviour problems?
If she seems to be doing fine with everything else, are these truely "accidents"?
If you don't think it's a behaviour problem it may be medical. Urinary tract infection?
only you know your dog best so ask yourself those questions and see where they lead.
Let us know how it goes.
