I've heard of a lot of people having one-off experiences with weed...the common thread between them seems to come down to anxiety. To be honest, I think the majority of 'bad' weed experiences stem from psychological issues (not 'problems' but issues, whatever they may be).
From how you described it, with everything moving around her and her eyes getting heavy, it sounds like she had a rather dissociative experience, but not too traumatic overall. I hate to say it, because it's so cliche, but that does possibly sound like her weed may have been laced with something extra...of course, that's taking a huge leap of faith to even venture to say that, and I'm not trying to make it sound like that's what happened.
Perhaps it was just a very potent strain and she wasn't used to the high THC content...it's really impossible to guess at small details about a person's experience getting high on weed unless you gave us her full drug and mental history, at least in my opinion.