They've both felt betrayed, fell in love quickly and share ties to the Windy City

By Dahvi Shira
April 26, 2011 07:00 PM

Kristin Cavallari and Jay Cutler are “very in love” and “so happy,” a source tells PEOPLE, which stands to reason: Cutler popped the question over the weekend.

So what do we not know about the romance of the reality starlet and her NFL star fiancé?

1. They fell in love fast
They only began dating last fall, and their relationship has been primarily long-distance, but by January, Cavallari, 24, admitted Cutler already had her heart. “I’m in love and it’s been great,” she told PEOPLE. “Things are really good.”

2. Cavallari has other ties to Chicago besides Cutler
“Chicago is great for me,” Cavallari has told PEOPLE. “My mom and that whole side of the family is there It’s been nice to hang out with my mom.” In fact, since the engagement, a source tells PEOPLE, Cavallari has been spending a lot of time out there.

3. Cutler has health problems, but they don’t hurt his career
Noting he “had no energy,” Cutler, who lost 35 lbs. in 2008, told the Associated Press that he’d been diagnosed with insulin-dependent diabetes. “It’s a little overwhelming to get that news and realize you’re going to have to completely change your life,” he said, adding that the diagnosis is not expected to affect his play.

4. They share a love of charity
Cavallari has worked with One Kid One World, helping children in impoverished and war-torn areas. She recently traveled to Kenya and El Salvador.

Cutler does volunteer work for young people with developmental disabilities through Vanderbilt’s Best Buddies program – and in 2007, he started the Jay Cutler Foundation, which partnered with Mile High United Way s Youth Success Initiative to help at-risk youth overcome obstacles and graduate from high school.

5. They’ve both felt betrayed
Cutler, 27, was verbally attacked by various NFL players after the 2010 NFC Championship game against the Green Bay Packers for sitting part of it out due to a knee injury and appearing disinterested on the sidelines. Cutler later said the criticism “bothered” him.

Meanwhile, Cavallari’s Hills pals Stephanie Pratt and Lo Bosworth staged a highly publicized drug intervention last year, telling her they were “worried.” A shocked and upset Cavallari vehemently denied claims that she ever had substance abuse issues.

Additional reporting by JENNIFER GARCIA