No, Katniss is the official Mockingjay, Rue inspired the revolution, but Prim started it. If Prim hadn't gotten picked Katniss wouldn't have volunteered then she wouldnt have met Rue who sparked the Mockingjay.
Reading has never really been joyful for me. The Hunger Games was one of the good movies that made me want to read more. Watching the movie and reading the book is two different things. I saw how much more detail you get when reading.
"My nightmares are usually about losing you. I’m okay once I realize you’re here." ― Peeta, The Hunger Games: Catching Fire (I can't remember if they put this in the movie or not but it is still wonderful.