It's a bit of a stretch to say that the 1958 low-budget horror movie Frankenstein's Daughter is actually about Frankenstein's daughter. At first, the title character appears to be teenager Trudy Morton (Sandra Knight), who mysteriously turns into a monster at night and runs amok. But Trudy is not the daughter of Frankenstein -- she lives with her uncle Carter Morton (Felix Locher), a scientist who has employed an assistant named Oliver Frank (Donald Murphy), and Oliver is secretly conducting experiments on Trudy by dosing her with a serum that turns her into a monster. Oliver's real last name is Frankenstein, of course, and so if the movie were about Trudy, it should more properly be called Frankenstein's Boss' Niece.
But Trudy's transformation into a nocturnal monster turns out to be a bit of misdirection, since what Oliver has been really focusing on is re-creating the experiments of his father and grandfather (the original Frankenstein), bringing dead tissue back to life. So it might be more accurate to call the movie Frankenstein's Grandson, but that's not nearly as catchy a title, so writer H.E. Barrie and director Richard E. Cunha come up with an angle that sort of justifies the title, as Oliver decides that he will improve on his ancestors' creations by making a female monster. He exclaims "Frankenstein's daughter!" as the monster comes to life, and that has to suffice. The other problem is that no one seems to have realized that the monster is supposed to be female, so it's played by a large male actor, with a disfigured face that's clearly male, except for hastily added lipstick. (Supposedly Cunha was so distraught seeing the masculine makeup for the monster that he left the set in tears.)
Like the Frankenstein in I Was a Teenage Frankenstein, who offers up a thin justification for making his monster a teenager, Oliver makes a ridiculous (and sexist!) excuse for why his monster must be female, reasoning that a woman will be more inclined to obey orders from men. He creepily hits on Trudy's friend Suzie (Sally Todd), takes her on a date to a secluded location and then runs her over with his car so he can extract her brain to use in the monster. Oliver is quite the sexual predator, constantly coming on to Trudy and then essentially slipping her a roofie when he gives her the drug that makes her into a monster in the early parts of the movie (that storyline is later dropped completely). He continues the tradition of the Frankenstein character being the movie's actual villain, as he uses his monster to take out his enemies, including Trudy's poor elderly uncle Carter, who's trying to develop a formula to reverse aging.
Not that Carter is an upstanding citizen, really -- he breaks into his former employer's lab to steal a chemical he needs, which attracts the attention of what appear to be the only two cops in the entire town. They are slow to believe Trudy about the monster attacks, partially because Oliver keeps undermining her, and partially because all the men in the movie clearly regard her (and Suzie) as a hysterical woman who can't trust her own senses. Even Trudy's boyfriend Johnny (John Ashley) dismisses her concerns until he sees the monster with his own eyes. He's more interested in throwing a happening teen pool party, complete with filler scenes featuring performances by a terrible rock band and vocals by co-star Harold Lloyd Jr. (son of the legendary silent film star). The movie struggles to reach feature length and then abruptly ends, as Johnny fights off the monster in one of the most lethargic fight scenes I've ever witnessed. The movie's title promises a female-driven update on the source material, but the result is a cheap B-movie that marginalizes and belittles its female characters. Mary Shelley would be turning over in her grave.