Errors in geography
So a flight from Chicago to New York would have almost certainly consisted of one to as many as three stops before arriving.
While flight crew service hour limits prohibited coast to coast non-stops, NY to Chicago non-stop was available in this era. A copy of a 1951 American Airlines schedule shows six non-stop flights daily from New York to Chicago, using the DC-6. American's longest non-stops that year were between New York and Dallas. TWA would have been competing on the NYC-Chicago, using Lockheed Constellation aircraft, but I don't have a contemporary schedule. TWA was flying NYC-Chicago non-stop as early as 1948, using much slower DC-4 aircraft, per a schedule from that year. This was TWA's longest non-stop in their short DC-4 era.
Incorrectly regarded as goofs
(INCORRECT goof statement: The Canon camera gift was not readily available in the USA in 1952. Canon USA's website "Sixty Years of Canon in the Americas" states their first office opened in New York in 1955.)
Incorrect: When Therese is first photographing Carol she is looking through the viewfinder, and the image goes into focus when she focuses the camera. This camera would not have that type of viewfinder.
^ The closeup of Therese through the taxi window is not a goof. It appears briefly in the Lincoln Tunnel scene because the scene is her memory of it. Therese's ride in the taxi after just seeing Carol again makes her think of her first ride in Carol's car. This film begins where it ends and the story is a circle between these bookends. In this tunnel scene the conversation between Carol and Therese is distant and barely audible, and Carol's face blurs and comes into focus because it is Therese's remembrance of this moment in time.
Incorrect continuity "goof": Near the end, Carol walks up to Therese's table with purse in hand and sits down with coat already on the back of her chair.