Brandon Blackstock and Kelly Clarkson Credit: Todd Williamson/Getty Images

She's been talking about getting hitched to boyfriend Brandon Blackstock for months, but when Kelly Clarkson finally came face-to-face with a diamond sparkler and a proposal, the singer was still moved to tears.

"It was a proper proposal -- very romantic," a source close to the singer told Us Weekly. "And yes, she cried!"

Clarkson, 30, hasn't been able to hold back her excitement since the Dec. 14 proposal.

"I'm engaged! I wanted y'all to know!" she shared with her Twitter fans one day later. "Happiest night of my life."

Her now-fiance, Blackstock, had been working with Beverly Hills jeweler Johnathon Arndt for months to design the perfect ring for his country gal in secret.

The result?

A stunning radiant-cut 6-carat canary diamond that Blackstock, 36, used to pop the question in Nashville, where the couple share a home.

"Kelly had a rough start with love, for sure, and a long dry spell," a friend of the "Stronger" singer said. "But Brandon was worth the wait."

Added another source: "She honestly thought she'd never find anyone and that she'd be single forever. But she's changed. You can see it in how great she looks and how happy she is."

And despite previously joking that she and Blackstock, the son of Clarkson's manager and Reba McEntire's stepson, may elope, Clarkson is now looking forward to having a big fete, pals say.

"[She] wants to go all-out," a friend told Us. "She'll keep it country, though."