If she likes the prequels, see if she wants to watch The Clone Wars and Rebels? The Clone Wars provides some amazing content between Episodes II and III, Rebels is a pretty strong spiritual successor to that while telling its own solid story and powerfully building up to Rogue One.
I showed a girl who is my best friend the franchise and she was VERY skeptical, the only positive things she felt about it were R2, Liam Neeson and Ewan, she was very "meh" to it in general. Since she already knew the Vader twist, we agreed to chronological order and after the first two prequels, she agreed she'd like to see the Clone Wars story with how attached she got to Anakin, Kenobi, Padme, and interested in the Clones without another time-skip. We watched the original 2D Clone Wars surrounding the canon 3D/CGI The Clone Wars and though she preferred to take our time the first few seasons in, by the Mortis arc after going chronological for the episodes, she was more hooked than me!
Best part is the Vader twist was kinda an echo in the back of her mind by the time we finished all animated Clone Wars that I actually asked her, you want Episode III next or you wanna save it for later due to some "spoilers" it gives the later originals? She said she didn't grow up with the franchise or have any nostalgia about what other movies do that she hasn't even seen yet, there and then she was invested in the prequel characters and wanted Revenge of the Sith.
So we went into Episode III and after all the emotional build-up and investment, she already got teary-eyed a few prior times, we watched Revenge of the Sith and when those 10-15 minutes came from Palpatine's reveal to Skywalker up to his dark side Fall after disarming Windu... she was in shock. In many ways despite having known the Vader twist, it was like seeing Anakin die in a way worse than literal death for her, betraying the Republic, himself, and her. Yet after The Clone Wars, it wasn't a lightswitch, it was actually sickingly undetstandable and it made her more emotional than ever.
Right around this time Solo was premiering in theatres so we went to see that, it kinda elevated her out of the gloom of Episode III. She fondly remembered Chewie from his supporting veteran role with Yoda (remembering him there from his guest time in The Clone Wars as well), loved the introductions to Han and Lando, surprised by the ending cameo and curious where things are going with him. Things still felt fresh after Episode III's end and that's one thing she was hoping for, as she was weary about the 2-decade time-skip into the original.
We watched Rebels after Solo, the first three seasons on my DVDs and having to watch Season 4 on her firestick, she really enjoyed that. Loved the story of the Ghost crew, continuing certain loose-ends from The Clone Wars, appearances from characters like R2 and 3PO, Lando, Bail Organa, Yoda, Vader, Maul! I also pointed out how little things like Saw and the Krennic/Stardust mentions were leading to the next movie, how the World Between Worlds was a big converging moment, and the show's epilogue only spoilering the Ghost crew's future.
We watched Rogue One and A New Hope back-to-back just yesterday, she loved the experience, now more ready than ever to watch The Empire Strikes Back and beyond.