One day after announcing thatshe and husband Offset are not together anymore,Cardi Bturned up at E11EVEN in Miami for an appearance as part of the annual Art Basel international art fair.

Rocking a rainbow-colored wig and see-through long-sleeve black minidress with a black strapless bra, the “Bodak Yellow” rapper, 26, walked the red carpet before heading inside the event around 3 a.m. Thursday morning. She was not wearingthe $500,000 eight-carat tear-shaped engagement ringshe’s consistently had on her finger since the Migos rapper, 26,popped the questionback in October 2017.

Though audience members were told Cardi would be performing at the event, an onlooker tells PEOPLE that she instead mouthed the words to a couple of her songs as they played and took pictures.

“She wasn’t singing or anything,” the eventgoer, who also sent PEOPLE exclusive video from the event, said. “You could tell she wasn’t her usual energetic self. It’s like she was trying to put on a good face but she looked sad.”

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Cardi B Performs At E11EVEN Miami During Art Basel 2018

The couple, who welcomed daughterKulture Kiariin July, remain cordial, she added.

“We are really good friends, and we are really good business partners — you know, he’s always somebody that I run to talk to, and we got a lot of love for each other — but things just haven’t been working out between us for a long time,” theInvasion of Privacyhitmaker added. “It’s nobody’s fault, I guess we just grew out of love, but we are not together anymore. It might take time to get a divorce, and I’m going to always have a lot of love for him because he is my daughter’s father.”

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While representatives forCardi Band Offset did not immediately respond to PEOPLE’s requests for comment, a source told PEOPLE, “They have obviously had huge problems for a long time.”

“They’re still very close and really do care for one another,” the source added. “Their priority now is their daughter, and they plan to be solid co-parents.”

RELATED VIDEO:Cardi BSays She and Husband Offset Are Not Together Anymore: ‘I Guess We Fell Out of Love’

Both Cardi and Offset are in Miami for Art Basel. A few days ago, she shared photos of her and her now-estranged husband kissing at a recent Lakers game.

Also on Wednesday, the newly single “Be Careful” rapper shared thefirst photo of Kultureon Instagram, writing, “My heart.”

Model Summer Bunni, the woman accused of coming between Offset andCardi B, issued atearful apologyto the “Drip” rapper on Wednesday, claiming responsibility for her actions.

“I feel ashamed,” she said in part. “It’s a lot, but just coming from me and toCardi Band to our fans, to her family to her situation, these were never my intentions and I never wanted to break up a happy home.”

Becky Randel

source: people.com