Well said. I have ADHD and was also remarkably childlike and naive in my mid teens to the point my freinds were sometimes shocked by my ignorance of other people's tone, meaning, intentions. I can relate to your post, and OPs daughter too.
My executive dysfunction and self absorption meant I needed a lot of alone time, which helped filter a lot of shallow, undesirable, dangerous people, and If someone unsettled or upset me I'd instantly ghost/distance from them, which again probably saved me from futher drama, abuse etc.
But I was totally unable to understand social hierarchies and deal with people who were not kind, nice or supportive. In dealings with people in my wider life, I was reflecting my own good nature onto others and expecting identical levels of honourable behaviour, morals, integrity etc in return.
I wasn't interested in boys, neither as freinds nor romantically, and wasn't into drinking and parties or clubbing, which meant I had 0 negative experiences with men. But I had a tough, miserable time at uni on a cutthroat course, with some very egotistical, sabotaging coursemates and bullying academics. I was exploited a little in 1 or 2 of my female friendships, and didn't spot the signs until late into my 20s.
My parents seemed to think it was willful ignorance on my part and saw no need to explain anything to me. Social skills training would have saved so much grief in the workplace, too, where poor social intuition meant I had a tendency to blurt things out and couldn't see obvious issues or skilled manipulation coming until it was way too late.
OP - If your daughter will agree to an assessment, it wouldn't do any harm. Her lack of self awareness is telling, most girls are very socially astute by 17/18 or at least beginning to develop strong self awareness. Being academically sound but socially clueless is classic female asd and adhd.
Have a look at autism communities online, as well as articles and books by Tony Atwood, Temple Grandin, Sarah Hendrix, Judith Gould (all experts in female autism). Your DD may not be autistic at all, but there is some overlap between ASC and adhd traits and other neurodivergent conditions so any ASC research will be informative.
Working on social skills training is useful, even if she catches up with her peers later. But girls often mask well. I masked with a kind of passive cheerfulness, without even noticing that was what I was doing. If there is an undiagnosed condition, you won't know till she hits a roadblock or has a bad experience that really hits her hard emotionally. That's what led me to diagnosis in my late 20s, I burned out completely and couldn't cope. Diagnosis and intervention at 14 or 15 would have saved me so much misery and suffering and prevented my worst adhd traits becoming entrenched.
There's no shame in having an ND daughter or being ND. She may well test negative, i know people who have. If she tests positive, with the right support she will be fine, but she will need it ASAP as support services for adults are like unicorns.