In this case the daughter still has only a 50% chance of being colour defective. Blue colour blindness is far less common, being present in just 5% of all colour blindness sufferers. The genes affected are equal in both sexes.
The cheapest days to fly are usually Tuesday, Wednesday and Saturday. While your information may be only anecdotal evidence, it probably confirms what FareCompare.com's careful study of airline supply and demand confirmed in a 2011 study of U.S. carriers.
(Okay, we'll try to stop saying Benjamin.) For the results, Kayak looked at both domestic and international round-trip flights in economy class; evaluating search dates between July 1, 2016 and June 30, 2017 for travel dates in that same period. Of course, What are the cheapest days to fly? is a complicated question.