You are correct: if you did not hide the rodent issue (i.e. did not commit fraud) and, moreover, the buyer chose to buy the house with knowledge of some rodents (so in deciding to buy with that information, she waived, or gave up, her right to complian or take action about the rodents), you should NOT be liable. That said, since the courts do not prescreen lawsuits to see if they are viable or valid, she can almost certainly file and initiate a lawsuit if she chooses, to which you will have to respond; but based on what you write, you should have a good defense to liability.