"It was perfect," Clarkson tells PEOPLE of saying "I do" in a super-private 2013 ceremony

Kelly Clarkson opens up about marriage, the joys of being a mom and her emotional new album Piece by Piece. Subscribe now for instant access to her exclusive interview and personal family photos, only in this issue of PEOPLE!

Don’t let her “Miss Independent” persona fool you – Kelly Clarkson was a big ol’ softie on her wedding day!

“I was so emotional, and I didn’t realize I was going to be!” the singer, 32, says of her 2013 nuptials to Brandon Blackstock in PEOPLE’s latest cover story.

Before welcoming daughter River Rose in June, Clarkson became stepmom to Blackstock’s kids, Savannah, 13, and Seth, 8. And at the wedding, her stepson started to wonder about the bride’s unexpected waterworks.

“During the ceremony, Seth looked up and was like, ‘What’s wrong with her?’ ” Clarkson recalls. “I was like, ‘I’m just so happy!’ ”

The “Heartbeat Song” diva – who releases her seventh studio album, Piece By Piece on March 3 – says she couldn’t be happier with her blended family.

“My best friend always say, ‘You just want to create the family you never had.’ I might be doing that,” Clarkson says. “In defense of my family, it happens. People fall out of love, and people go separate way. People are human. I’ve accomplished a lot, but I guess the biggest success I want is that whenever I die people will say, ‘She was so successful as a mother and as a wife.’ That’s kind of a big goal.”

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