If you are referring to the novelizations and expanded material for the ST, I am 100% comfortable admitting that my knowledge of them is *spotty* at best... so feel free to inform me of anything I don’t know.
I know that ADF’s novelization fo TFA definitely played up the assault vibes of Rey and Kylo’s first scene together from *her* perspective... while also giving him more affably evil dialogue. I know that the TLJ novelization varied a little bit between the junior and adult novelizations, but both seemed to want to increase the idea that Rey was suffering loneliness when she reached out to Kylo, while neither was necessarily more informative on substance, but more in explicit tone (an advantage writing can always have over film, where film’s advantage is saying much while saying little).
I know that most TLJ-TROS-centered material became more “Rey is intrigued by and compassionate towards Ben” as time went on... but that an early comic released after TLJ had Rey and Poe confirm that, yup, they’re “torture buddies” thanks to Kylo. I also know that “The Rise Of Kylo Ren” being published right now is trying to walk back some of Ben’s crimes, by making it so that the Jedi Temple was blown up by someone else, stunning him, and by contriving a method for the other students to instigate fatal combat with him as issues pass. As you might be able to tell from my tone and the word “contriving”... I regard this as shameless white washing that is ultimately insubstantial and meaningless as far as the movies go, and especially in regards to what Rey knows.
(By the by, get ready for a longer argument, and if it bores you... please skip down to the other book recommendation from the current Star Wars continuity. I feel it’s good enough *everyone* should like it, regardless of whether or not they like “Reylo” or not.)
The films’ substance is all that really matters to me regarding this. And the substance of 97% of Kylo’s actions towards Rey are violent, traumatizing, manipulative, or otherwise callous and life-endangering. I’m *not* going to list them *this* time, because I’ve done that far too much and it’s obnoxious. If you’d like me to, ask.
The bigger issue is that, from TLJ’s second conversation between the characters on, in my opinion, Rey is twisted to ignore damage and violence done to herself and her friends and have a pro-Kylo/Ben bias, and to care about him and keep offering him second and third chances... even while he continues to hurt and “abuse” her.
I also reject the idea that Rey has any actual similarities to Kylo that could trigger her attraction to him as kindred spirits; the scripts are ignoring her other friendships, like with Chewie (on Ach-To), or with Finn (in general) because they threaten the “she’s lonely” narrative, and Kylo’s problems are his own damn fault. So, not only do I think Rey is being written as being attracted to an abuser... but I believe there’s no solid writing reason for it; it’s just happening, because the script wants it to.
I get the argument about “Ben Solo” being such a distinct and separate personality from Kylo, and Kylo being created by Palpatine-induced Force Shizophrenia... it’s just a story element that, to me, can only solve the abusive relationship dilemma if we remove so much of Ben’s agency and *existance* when Kylo is dominant... that Ben kind of ceases to exist in the films until TROS’s Act III... at which point I’d question whether this ethereal “Ben” character should really serve as Rey’s romantic interest, considering the shallowness that the idea inevitably depends on. But As long as he has any real agency and any amount of self-control... then the relationship is still abusive.
For the record, I don’t think that Rey and Kylo/Ben’s relationship had to be abusive; there were ways to write away from that. They just didn’t follow them, and no amount of book white washing or after-the-fact clarification can help that.