These look like the later signature that they have. Still, that seems like a fairly easy signature to duplicate. And it would be a lucrative one for forgers. I understand she was rather reclusive and was not available for the most part in the era these would have possibly come from.
There is a dealer who seems to cycle through Bettie Page autographs fairly regularly. I've been a bit incredulous of what I've noticed coming from there. These look better to my eye...although I'm not an expert.