The last Sharknado movie ended with Fin and April (Reid) agreeing to re-marry, and at the start of this film, it's quickly established that April is now pregnant, making clear a few things: a) the movie is going to put her in a lot of mortal peril, b) Tara Reid isn't going to be doing much in this movie, and c) the film will end with a birth, of course. And yes, that is Bo Derek playing April's mother.