Interesting. Until you pointed out about her user name, I also thought maybe the OP & her brother were very young adults, in their early 20's, in college or something, with no credit cards. But in the OP's signature, it actually lists her blog URL as a Canadian Disney Mommy. Get this, the blog is FOR traveling with young kids, especially to WDW. In her own words she says she has traveled extensively, even as a kid herself with her family.
So, I find it odd that she travels so much and has no credit card. 
Maybe her next blog post should be about the need for credit cards while traveling.
In the OP's defense though, I have
never traveled with Spirit Airlines. I usually fly with American or United and when absolutely forced to, with Delta. The first two have always given me free water. (I don't remember about Delta.) I usually have to ask for no ice, as they pour it from pitchers or a bottle and add ice to the cup. It would never occur to me that I'd have to pay for WATER.
Food, yes. Snacks, nowadays yes. Other beverages, yes. Water? No, never would have occurred to me. And I wouldn't have known to read up on it. (I DO carry my own empty water bottle with me past the TSA, while traveling, and fill up before getting on the plane. As a PP said, sometimes, due to turbulence, the flight attendants cannot take out the beverage cart or even walk up the aisle to give a single person service.)
However, I carry a credit card for traveling, as in this case, there are times when traveling where they only take credit cards, i.e. car rental deposits or advance hotel reservations. I still can't fathom traveling so much and NOT having a credit card for such emergencies. Anyone who's had their plane delayed or diverted knows there are a myriad of unforeseen occurrences that could happen where you just need that extra money which either would be unsafe to carry or unexpectedly needed.
