I'd say a proper response is one that conveys empathy and validation of her feelings. Grilling her for specifics could feel threatening, but showing concern or curiosity about her feelings could make her feel safe enough to open up. Possible things that could be part of a proper response: "Oh, yeah, I've noticed a few of the guys are unaware of social cues. Has anyone done anything that felt threatening?", "Yeah, sometimes guys don't realize how they come off. I'm sorry they've made you feel that way.", body language that is non-threatening like sitting down, relaxing your shoulders, standing far enough away, facial expressions that reflect the feelings she's expressing to you.