Maybe somebody else suggested the word complex to her but I think we can be pretty sure this has a factual basis. There was no pressure on her to make this up and certainly Colonial Village wasn't mentioned in the media discussion of the case at the time of the letter and interviews. If you want to take her other statements at face value, Zimmerman first saw Martin at the mail kiosk there and followed him to TRATL.
Colonial Village wasn't mentioned in the media, but we know the media got footage of GZ in the police station that wasn't authorized for release (the video that showed him in the police station supposedly showing that he had no injuries). I think its quite possible it had been released to Crump that GZ says he first spotted TM by Taffe's. What would be the best story to put forth that would make TM walking by Taffe's house seem benign?
I am not suggesting we know that this was something made up by her with or without someone's prompting. I do think its seems pretty odd that she would offer very few details in this written "statement" (meaning this detail carried some significance), but she never mentioned this point in the Crump interview, in the media (that I recall) or in BDLR's interview. In the BDLR interview, she focused on TM telling her it was about to rain and that he was about to get inside a thing, more specifically a mail thing/shed/covered area. He had run into the gated place to the mail thing to get out of the rain (in the letter, she said it started to rain so he took the shortcut through another complex). I guess its possible she just forgot about the route through the other complex or was mistaken in the timings of when it rained and how they triggered specific actions by TM, but why mention that specific detail of cutting through another complex because it started raining, but never mention it in the BDLR interview?
I think its possible (even likely IMO) that the walking through the other complex was part of a early narrative to explain why GZ saw TM by Taffes (information that had been leaked to Crump). This statement would have provided cover for TM being seen there. The question with a less obvious answer is, why was walking through a neighboring complex never mentioned again? Could it be that while this excuse provides cover for TM, it also provides cover for GZ, giving him a legit reason to call NEN?