That was a very good movie (and a shocker in its time). The lady got an Oscar for her performance.
She didn't although nominated and she's a he and still is. Which was the point of the movie. The most implausible thing in that movie is Forest Whitaker playing an overweight British soldier with a funny eye!
I was once an extra in a movie with the same director, Neil Jordan and actor Stephen Rea which also featured a transgender character played by Cillian Murphy. (Neil Jordan must have a thing about transgender?) In the movie Murphy looks good, cute even but on the set even though wardrobe and makeup did a great job. He just looked like a man in drag.
Which brings us to Caitlin in real life she wouldn't be cute at all. She is over 60 after all. You can do lots of magic with cameras but I'd say if you met her without make up she'll look just a bit mannish. At her age there isn't much that can be done to reverse all those years of testosterone.
But good luck to her even if I hate the whole Kardashians as celebrities thing. What did they ever do except be famous for being famous?