Does the ESTA 72 hour approval include weekends?
 

So I have a work colleague that needs to travel with me to the US. She got her ESTA but then realized that a number was off in the passport so applied again with the correct info but received pending approval within 72 hours.

Considering it's Friday of Thanksgiving weekend and we need to travel Monday morning, is it reasonable to expect approval in time?

I've seen ESTAs approved in well under an hour at all times of days, including on US federal holidays and weekends. If it takes longer than 24 hours for approval, that's way more the exception than the average for most of those applications which I've followed closely -- even when some are given indications that it's pending approval within 72 hours. If she's not good by Monday morning, the chances she needs a visa are much, much higher even were the application submitted with no weekend or federal holiday around.