This doesn't wash. She notices him enough to see a "panicked look on his face" and to think he's "running from the police" (even though he wasn't running), and then decides to just turn around and look the other way? Then Brewer immediately comes up to her and asks about the man and she doesn't know what man or whether or not he bought a ticket? I think she just didn't want to admit that she supposedly let a guy sneak by her without noticing him at all.
The "panicked look on his face" is what she noticed when she initially saw him. "Running from police" came after Brewer followed the guy into the theater and had her call police. The difference is the extra information provided by Brewer (in both word and deed) and in the extra time that allowed her to put two and two together. Before Brewer showed up, he was just some other guy on the street, albeit some dude with that fashionable panicked look to him. The assassination happened a three miles away, and she didn't know yet about the Tippit killing. Why would she automatically be expected to immediately assume that he was important in any way?
In her affidavit, she saw that she responded to Brewer's initial question with a "No." In her commission testimony, it's ""No; by golly, he didn't." Brewer told the commission she said "no, she hadn't." The only different account is in Brewer's affidavit: "I asked the girl if she had sold the man a ticket and she replied that she did not think so, that she had been listening to the radio and did not remember." This answer implies that she knew who he was talking about, ergo she'd seen "that man"