Here is a classic reference: Nesbitt, Paul; Pond, Alonzo; and Allen, William - The Survival Book, 1959 - pg. 204

"Alcohol, salt water, gasoline, blood, or urine - any of these liquids which desert and sea castaway romances say men have tried as substitutes for water -only increase dehydration, because all contain waste products which the body must get rid of through the kidneys." This caution is repeated throughout the book.

On page 14, Table 1-2, the indicate that a "man" (no walking) with two quarts of water in a maximum temperature of 90 degrees F can last for nine days, so this lady was well within those parameters. The fact that she was immobile, and probably of slighter body build would have been critical factors (also liters are quarts on steroids). Maximum temperature is crucial; at high temps, survival time does not increase despite have up to four quarts. Resting and staying in the shade, out of the sun, are critical. Probably her injury paradoxically helped save her...

The source for this table is a 1947 publication - Physiology of Man. I'll bet it is based on WWII experiences and data.

Your notion to contact the author of the piece is excellent! Can I do anything to help you??