I'm pretty sure she's a virgin as she never did anything with her boyfriend at least from what I gathered from what she has said during the game which is why my post above shows 2 altered scene texts for the 2 scenes..
Yes, exactly. I would have expected some mention somehow. Like in the version you posted.
I don't think she was a virgin. Or at least if she was, she had done everything else but the actual penetration thing (From dialogue Kell dropped.)
Points in your favor however is that, women Kell's age who are virgins usually do not have a breakable hymen as it "erodes" over time and a virgin Kellys age would be able to have sex without discomfort except due to stretching, or dryness. Second point obviously not a problem Kell had.
Not sure what you mean by "everything else", but I pretty sure she haven't had vaginal sex yet, and probably also no anal. Handjobs and maybe blowjobs, ok, maybe, but not much more. At least how I remember it. Maybe I need to do a full playthrough again...
Regarding the hymen, you are correct, but lack of a hymen or other discomfort doesn't make the first time less special from an emotional point of view. Which is what I expected Kelly to acknowledge somehow.
On the other hand, I did love the contrast between the perfectly romantic hotel room and the overexcited dad, vs. the bathroom scene. It felt extremely real and believable, like almost everything else in this game. Which really makes it stand out in my opinion.