Her changes in behavior aren't that surprising, considering what's been happening to her physiology lately. I would be very surprised if her mind wasn't affected in some way. I can't tell if it has actually changed her personality or made parts of it more dominant than others.
Whoa. She could be turning as single minded as an insect? Sting or be stung? The hive is the only thing that matters? Losing her sense of humanity? Of human ethical behavior? Hmmm?
Nobody's talked yet about something that Vincent Price mentioned in the 1959-sequel: insects are VERY short-lived compared to humans. What if she inherited this feature as well?!?
So, bees are inherently assholes, and Cynthia appears to be receiving that asshole mutation. On the other hand, Sam should manifest the nobility inherent in snakes (at least the solid kind).