Interesting timeline.
January 24th: FBI agents interview Mike Flynn at the White House.
January 25th: Sally Yates is briefed on the interview by the agents who conducted it.
January 26th: Yates requests a meeting with White House counsel Don McGahn; it takes place in his office that afternoon, and Yates informs him that Flynn had been interviewed by the FBI two days prior.
She also informs him that Flynn was lying to the public and the VP and others about his conversations with the Russian Ambassador, which left him open to being compromised by the Russians, if not already compromised by the Russians.
January 27th: Yates returns to Don McGahn's office at his request at which time she explained to him that every time Flynn's lies were repeated it increased the chances of compromise.
McGahn asks Yates if he could see the evidence against Flynn.
(During the meeting, McGahn does not mention to Yates, the acting attorney general, that Trump will be signing his travel ban that day.)
Coincidentally, also on January 27th, 45 summons FBI Director James Comey to dinner at the White House, where he asks Comey if he himself is under investigation.
(When I said 'coincidentally' I meant that sarcastically of course. There was nothing coincidental about it.
Obviously 45 wanted to know if the FBI had anything on him. By his own admission, he asked Comey about that three separate times.)
January 30th: Yates calls McGhan to let him know he can review the underlying evidence against Flynn. Later that day, she announces that the Department of Justice will not enforce Trump's travel ban. She is fired that night.
Sally Yates Provided a Helpful Timeline of the Mike Flynn Saga