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.
That's when the airlines adjust their prices to match whatever deal another airline ran on Monday. And it's still good advice. However, researchers recently found that weekends are overall the best time to buy. Also, the day you fly makes a big difference, with Tuesday being the least expensive. Sites like Matrix, Bing Travel and AirfareWatchdog can help you find cheap flights or predict when prices are going to be the cheapest.