The problem here is that, in most situations, people are not contracted employees of a company. By this, I mean that when you enter into employment you do not sign a contract of employment specifically stating that you can only be terminated for cause.
Without such a contract, we are "at will" employees. This is true for almost everyone. At will employees can be terminated at any time, with or without cause. So, your daughter would not have any external legal basis for a suit. There would need to be some internal company policy that created the requirement for there to be "cause" before termination.
That means that she'd need to obtain that company policy.
Her first step needs to be filing for unemployment. The purpose here is to use that process as a means of discovery. She should state that she was forthright with the company, did not fail to disclose anything and that the company did not have a valid violation to use as a basis for termination. The employer will have to prove otherwise, because to block unemployment (a state law right), they have to prove cause. She should request their company policies too, concerning discipline. How that hearing turns out will tell her a lot about what she may or may not have, in terms of an additional claim.
I want to caution you here though. Winning unemployment does NOT mean that she has a wrongful termination claim. Plenty of people get unemployment but very few have a wrongful termination claim. Getting unemployment would be a good financial victory for her, and it might reveal (through the company policy) whether an additional claim of wrongful termination through violation of their own company policy would be useful.