Over-sensitive or too sensitive is a term often used when women are upset by threats, victimisation, harassment, marginalization, etc. The implication is that women should have thicker skins, or should, in short, put up with mistreatment without complaining. Accusations of being too sensitive are commonly used as a Silencing tactic, closely related to You're being emotional and Suck it up and deal.
The term "over-sensitive" or "too sensitive" has some other implications too: it makes it sound like there is some line above which it is alright to be be sensitive, but that the current incident does not cross that line. As such, the "over-sensitive" tactic is sometimes also a Concern troll tactic: "I agree that there are problems that we should be concerned about, but this is not one of them."