I'm not completely sure, but the biggest commercial tort enclosures I've seen are around 2' x 4' or so (which is by no means big enough for an adult)....

I think it would be fine in something that sized for quite awhile, like you mentioned, they grow slowly.. I would make sure your wife's coworker knows that EVENTUALLY they will need a larger enclosure than what is pre-made and available, but it work for awhile.