“Some Tauriel fans:” She could have been in the book, Tolkien just didn’t mention her.
Did you guys know that during the spider fight in Mirkwood, Doctor Who accidently crashed the tardis into a tree causing a worm hole sucking the dwarves in and transporting them into deep space. Luckily for them they are picked up by Red Dwarf and Bofur traded crocodiles with the crew in exchange for passage back to Middle Earth. Suddenly Harry Potter flew into them causing a second worm hole that took them back to the forest.
It could have happened Tolkien just didn’t mention it! XD