She loved Super Mario RPG, which was a legitimately good game and had brilliant comedic writing, so she honestly deserves better than the weeb trash that is the remake, and the original was honestly never that good either. FFVI, FFIV, FF Tactics, FF IX, FF X, Breath of Fire 2, Suikoden 1 and 2, Xenogears, Vagrant Story, these are all much better games that I imagine she'd probably enjoy more.
FF VII has a few excellent things going for it that are, in my opinion, responsible for the overwhelmingly positive reception it received and the legendary status it has enjoyed since.
Iconic character designs: It's hard to deny this, even as the detractor of the game that I absolutely am. Cloud simply looks awesome, so does Sephiroth, Cait Sith and Red XIII are weirdly cute and very 90's looking, Cid is the rough and tough every man, Vincent is edge lord gold and also very 90's, Barrett is.....well kind of a miss, and Tifa makes weeb dicks hard. Iconic character designs are a huge part of lasting appeal, I mean look how people freaked that Sephiroth was coming to Smash. Hell, even I love playing as him, he just looks fuckin rad man! And that sword! Shame how badly written he is in the actual game, and how his character arc started out so interesting but ended on a flat, one note villainous archetype......but he looks cool and has a long ass sword so folks like him, me included.
Amazing sountrack: I'm not gonna elongate this; the game's got jams man.
Beautiful set designs/prerendered backgrounds: Iconic, unique locales tend to stick to a person's mind when they experience a piece of media. Even if you can't remember the name of it, you'll remember how it looks perfectly, and maybe even the song in your head. For example, there's a part of FFVIII where you play as Laguna that I can't remember for shit in terms of narrative or location names, but fuck I remember it being a really cool looking city with a fun night life, very evocative of the 30's through the 50's, and that image really sticks with me. FF VII has several locations like this, while most games only have 1 or 2, maybe 3. Makes the game stick out in people's minds more.
That's just how I see it in any case. I started out on Super Mario RPG when I was quite young as well, and I honestly just didn't find FFVII that much fun to play. I didn't like the materia system, I didn't like the battle system, I didn't like how limit breaks were handled, and I ultimately found the narrative underwhelming, particularly the conclusion and the "twists." If she really like Super Mario RPG in its brilliant simplicity and outstanding comedic writing, then I find myself thinking that she may not love FF VII as much as you may assume, but then again I could be way off base and she could find it utterly outstanding, who knows? I will say that FF VIII landed a lot more for narratively but failed in game design and the junction system, FFIX is damn near perfect and it doesn't get the love it deserves, FFVI is simply the best numbered FF by a country mile and nothing comes close, FFIV is a bit dated and difficult, but had a satisfying character arc for the protagonist and a satisfying conclusion, and Tactics has the best writing of the series. I also adore FF XII, but that one's a bit controversial as a lot of folks hate it, but I think it's brilliantly written, even if it's just a rip off of Star Wars ultimately. My genuine opinion is that FF's I through III are completely skippable, and that VII was ultimately disappointing, but it managed to ride this wave of fortune due to embracing 3D graphics at a time when it could be accepted and embedded into the average gamer's nostalgia bank, and as such it will forever be beloved. If it had come out on the SNES with pixel art, noone would be discussing it today. FF VI did come out on the SNES with pixel art, and is often discussed as a potential for one of the best RPG's of all time, and I think it deserves notoriety for that.
In summary, I want a beer and a steak.