It’s taken much longer than she ever imagined but Helena Bonham Carter finally sees her wish come true with this week’s film version of “Four Letters of Love.”

“I was so eager to be a part of this,” Bonham Carter, 59, said by phone from London of Niall Williams’ celebrated romantic Irish fable.

“It’s because of the longevity of my relationship with the book — I’d been given it by my mom about 25 years ago. I read it and I loved it. I love Niall Williams! I think partly because I wanted to be in the book.

“It definitely creates an enchanting spell. You know when you love a book so much you want to just creep in and live inside? It was that instinct.

“Now, after working with Niall who’s written the script, this is one of the most poetic scripts I’ve read.”

Published in 1997, “Four Letters of Love” was Williams’ first novel and immediately became an international bestseller. It’s since been published in 20 countries.

“At that time, I even looked into getting the film rights, even though it’s not the most obvious thing to adapt.”

That’s because “Four Letters” is sweet, funny, fanciful. Generational stories of parents and their adult children with what might be dubbed Irish peculiarities.

God speaks directly to Pierce Brosnan’s painter. There are ghosts and an invocation to cure the crippled. A young woman realizes, just a day later, she’s married the wrong man.

That would be Isabel (Ann Skelly).  “I really wanted to play Isabel,” Bonham Carter allowed, “but I was aware that other people had the rights and it didn’t really happen. Then, 25 years later, it came back and I’ve graduated to play the matriarch.”

Bonham Carter’s career has recently triumphed with award-worthy portraits of the troubled Royal, Princess Margaret, and Hollywood’s legendary Elizabeth Taylor.

Was she aware that one day it would be natural for her to play them?

“No. Not at all. When they asked me, I couldn’t quite see the similarity or the point at which I was right for them. So, a lot of work had to be done with both.

“Once you watch them, you try to capture and bottle an essence, an idiom, a way of being, rather than an imitation.

“So, I was very tough with it, but it was a risky thing. There were a lot of ways for me to go — but I also have great people around me, my magicians, to help me with creating hair and wardrobe. So many things can happen there.

“But if you’ve got the talent of those people, they’re going to help you a lot.”

“Four Letters of Love” streams on Plex