Sources tell us she died Wednesday in Miami. We don't have details yet about the cause of her death, but a since-deleted social media post claimed she was in Miami to undergo a "mommy makeover."

Jacky Oh!'s real name was Jacklyn Smith, and she and DC met in 2015 ... the same year he made his premiere on MTV's hit show "Wild 'N Out."

Jacky was already being featured as one of the show's "Wild 'N Out" girls at that point.

Jacky was no longer on 'WNO' ... she'd gone on to launch her own lip gloss line called the J Nova Collection.

Of course, DC is still one of the show's biggest stars, and we're told he was actually in Atlanta shooting new episodes when he got the tragic news about Jacky's death.

The "Wild 'N Out" social media page posted about Ms Jacky's death, writing, "We are deeply saddened by the passing of Jacklyn Smith, known to the world as Jacky Oh, a talented Wild 'N Out family member whose impact will be forever treasured and missed. Jacky Oh was a loving friend and beloved colleague of the Wild 'N Out cast throughout five seasons."

They continue, "More importantly, she was a tremendous mother to three beautiful children. The BET Media Group extends our condolences to the Smith family, DC Young Fly, B Simone, Nick Cannon and all friends who loved and cared for Jacky Oh during this difficult time."

Although Jacky and DC never married, they remained a couple and had 3 children together -- daughters Nova and Nala, and their son Prince was just born last year.

Jacky was just 32.