She had to fill out an application and get approval to get the names unmasked. The only law that has been broken was the Flynn leak. So, unless, she leaked Flynn, she's okay. To investigate why/how she was approved to receive the names, would require reading the applications.
Application? So what? Who reviews the application and what metrics do they use for approval? The fact that this transcript of routine and continual Russian surveillance makes its way to the highest levels of the Obama White House strongly suggests that the Americans were identified and unmasked at lower levels. Then we have the subsequent Obama direct order expanding the distribution list of this raw data with the clearly foreseeable consequence of leaks--which is what happened.
This whole thing stinks.