Meg Cabot is missing Princess Mia already.
"I always saw the books going on just until she turned 18," says Cabot. "But now I'm like, wait a minute."
Princess Mia, in case you haven't talked to a tween girl in the past eight years, is the title character of the Princess Diaries, Cabot's 12-book, internationally bestselling series about a New York City teenager who discovers she is really the daughter of the ruler of a small European nation.
On Tuesday, the 13th — and last — of the Princess Diaries, Forever Princess, will roll into bookstores. It takes Mia, who began as a freshman at Albert Einstein High School, up to prom, graduation and her 18th birthday.
Publishing the same day: Ransom My Heart, by Princess of Genovia Mia Thermopolis, with help from Meg Cabot.
"It's Mia's senior project," Cabot says by phone from Key West, where she lives with her husband. "It's a romance. Princess Mia is getting better reviews as a romance writer than I ever did! I'm so jealous."
Cabot's first seven published books were romances for adult readers. "I published them under another name, though. I didn't want my grandmother to know about them. They were pretty steamy."
So is Ransom My Heart, the story of Finnula, "an adventurous beauty," who kidnaps Hugh, a rich and handsome knight, to get dowry money for her sister. The Princess Diaries books are for young adult readers, but this one "will be in the adult section of the bookstore," Cabot says.
What's the difference between middle grade, young adult and adult books? "It's the level of kissing, actually. No kissing in middle grade, no sexy time in YA. In adult fiction you can do anything."
Ransom My Heart is a book she wrote some time ago. "But the medieval market wasn't really hot then," so she stashed it away when the Princess Diaries took off, along with her other series — Allie Finkel for kids, Avalon High and Airhead for teens, Heather Wells and Queen of Babble for adults — and assorted other books.
Does she know exactly how many books she has written? "No, I don't." Cabot says she has always written stories, "since I was a little kid.''
"Recently I finished a book, and I had some time off. So I thought, now I can write this other book that's been bouncing around in my head.
"My husband said, 'What the hell are you talking about?' But I figure, it's like Tiger Woods. When he gets some time off, he wants to play golf."
Ransom My Heart turned out to be a handy solution to an odd problem. "Parents don't want to see sex in these books" for young readers, Cabot says, "but that's all the kids want to read about.
"Lots of them have grown up with her. Girls are always asking me when Mia is going to have sex. But you feel like a parent toward your characters. There's no way I was going to write a detailed sex scene about Mia."
So she let Mia "write" the sex scenes in Ransom, and some of them are excerpted in strategic locations in Forever Princess.
Cabot intended to publish Ransom only online, but her publishers jumped on the idea. "So I thought the money from it had to go to Greenpeace," Mia's favorite charity, Cabot says.
"Living in Key West, we're so conscious of the reefs being destroyed. We want to live here for a long time, and if the glaciers keep melting we'll be under water."
The publication of Forever Princess and Ransom My Heart will be celebrated Friday in New York City with a gala sold-out reading and an online auction of tiaras created by such celebrities as Julie Andrews (who starred in the two films based on the Princess Diaries), Vera Wang and R.L. Stine, to benefit teen programs at New York City libraries.
How does Cabot, who's 41, channel her inner teenager? "I read all the message boards, get lots of e-mail from readers, do signings. I know the problems they have because they constantly write to me about them."
In high school in Bloomington, Ind., she had the same kinds of problems. "Well, someone wrote me that pictures of her naked had been e-mailed around her school. I didn't have that problem."
But, technology aside, Cabot says she understands kids who feel like outsiders. "I really just felt like a freak as a teenager. It's interesting to find out now that everybody felt the same way, but nobody talked about it."
Cabot's characters do — including Mia, who despite her royal heritage has a raft of problems with boyfriends, frenemies, annoying family members and her wobbly self-image.
"I get all these e-mails from girls who say, 'OMG, I'm just like her . . . except I'm not a princess.' "
Colette Bancroft can be reached at email@example.com or (727) 893-8435.