Her crime may have been to with withhold info from Mossad. Trump might have been having back channel comms and keeping FBI out of the loop. NSA would have known about the calls, but FBI is the lead on counterintelligence so they would have had a "need" to know
The highly classified whistleblower complaint against Director of National Intelligence Tulsi Gabbard is related to a conversation intercepted last spring in which two foreign nationals discussed Jared Kushner, according to U.S. officials familiar with the matter.
Ok so maybe the NSA didn't hear them talking to anyone in Trump's circle. Sounds like they overheard a bunch of foreign officials chatting ABOUT someone in Trump's circle. Suppose it was Kushner: the implication would be that Kushner was compromised. In that case, withholding the report from the FBI would be a big deal.
Of course the other implication is that Kushner knowingly had back channel communications with these Muslims, in which case it would make sense for Tulsi to give the report to Wiles but not the FBI.