My wife can read a novel a day..
I can believe that. Most people read at less than 300 words per minute because they read one word at a time and they "think" the word, i.e., read it to themselves. The key to speed reading is
1) stop reading one word at a time while thinking the word. One can see a word and understand it without mentally saying it to yourself in your mind.
2) Look at two, then three, then four words at a time without mentally saying each word. Build up until you can see and understand a line at a time without mentally saying any word in your mind yet understand what you read.
3) began reading two lines at a time, then three, then four. Eventually you can glance and read the entire page at one time.
Admittedly, not all people can do this, but somewhere along the way they will build their speed to over 1,000 words per minute, or more. A typical page may contain around 600 or 700 words. Reading at 1,000 words per minute is reading a page per minute. A 300 page novel would take 300 minutes, which 5 hours. Not even half a day.
EDIT: There are other methods as well. One is where the reader scans the page for words which are obviously subjects, verbs and objects and ignores the fillers, connectors and other trash words that don't really carry content. Sometimes, however, "and"'s, "if"s or "but"s are missed and wrong interpretations are taken.