dry run of some standard operating procedure for delivering messages, practice for wartime.

or she was a spy/compromised and stealing secrets from her employer that she was as clueless about as any casual observers today; she did this on the daily but she died or got arrested this particular day. maybe her husband wanted the weather for his horsetrack gambling ring or something.

for every actual important encrypted message, there are a ton of similar messages and message transports of lesser importance.

(i'm assuming it's not the case that this is the plausible deniability part of some sort of steganography scheme)