Not to be gender biased, but women will usually be more particular when there’s a “friend” request from someone they don’t know. An instinctive measure. Even if they know the person, this from work or they went to school together, they’ll still choose not to friend them for a variety of reasons, this usually from over analyzing the issue.
It’s a simple harmless “friend” request, no harm no foul. Yet, what they’ll do is think about it, or they need to discuss it first. Men are generally, “Hey, I know …