Ice-Fabio / X17 1 / 9
Ice-Fabio / X17 1 / 9

In recent months, Miley Cyrus has seemed determined to show the world that she's all grown up, from pole-dancing onstage to getting "just breathe" tattooed in her bikini top area to showing the Queen her cleavage to stepping out this week in a bra-baring outfit.

But is the rapidly maturing starlet ready to make a Grand Canyon-sized leap into adulthood?

On the heels of rumors that she and her 19-year-old boyfriend-cum-"Last Song" co-star Liam Hemsworth are shacking up at the Cyrus family homestead (denied by all parties) come rumblings of a question-popping.

RELATED: See more photos of Miley

The engagement speculation was sparked by a ring that Miley was sporting on her all-important finger while out and about in Los Angeles on Wednesday.

The paparazzi, whose constant presence Cyrus ranted about on her Web site last week, zeroed in on the bright and shiny object decorating her dainty finger. She later covered up her hand with the sleeve of her sweatshirt.

Miley and Liam have been inseparable since hooking up last summer, even spending the holidays in the actor's native Australia with his family. But could there really be an ill-fated teenage wedding in the works?

Not according to the pint-sized Disney powerhouse's rep, who assures Wonderwall, "Miley is not engaged."

RELATED: Check out Miley's beau and more breakout stars of 2010

Still, there are some who are convinced that she has betrothal on her mind.

"She is looking to marry early and have kids at a young age, and she, right now, thinks ... that this guy is Mr. It," E! News' Ken Baker told Ryan Seacrest on his radio show last week. "That this is the guy that she is gonna marry and it's gonna happen quickly."

Miley hasn't been quiet about her affection for Liam, whom she was first spotted making out with in August as they said goodbye at the Nashville airport.

"I've never gotten along with someone so well," she told Seventeen of shooting "The Last Song" with Hemsworth. "I was a little anxious about making this movie; I wanted everything to be perfect. To go on set and feel insecure was a totally new element for me. But he felt the same way. He admitted his insecurities, and it was really nice to have someone who understands me for once."

RELATED: Check out Miley's artist page at MSN Music

The actor was also the driving force behind her decision to shut down her Twitter account.

"We've decided that any type of relationship that we have, we will always just keep it very D.L.," she explained. "First and foremost, we are best friends, so that's what I tell people all the time."

And whether or not she decides to make a run for the altar years before she can legally raise a glass of champagne in celebration, Miley has made it clear that she's not the standard-bearer for teen behavior.

RELATED: Miley poses for Harper's Bazaar

"My job isn't to tell your kids how to act or how not to act, because I'm still figuring that out for myself," she told the February issue of Harper's Bazaar. "So to take that away from me is a bit selfish. Your kids are going to make mistakes whether I do or not. That's just life."

Read more Hot Gossip