Cheryl has hit back at "nasty" rumours regarding her mum's involvement in her split from Liam Payne.
The singer and One Direction star Liam announced they were breaking up on Sunday, saying: "We still have so much love for each other as a family."
Now, Cheryl has called out "false articles regarding my mam".
"She is a soft and kind woman who doesn't deserve to be dragged into something that has nothing whatsoever to do with her," Cheryl said.
Tabloids reported that Joan "could be to blame" for the end of Liam and Cheryl's relationship.
"I don't know why they involve her in stories about me," Cheryl wrote in a note posted to Twitter.
The 34-year-old described Joan as a "soft and kind woman" who should be left out from the fallout from her split with Liam, 24.
Cheryl had previously criticised The Sun for an article suggesting she and Liam had put on a loved-up display at the Brit Awards as a stunt.
But after admitting to relationship "struggles" in March, the pair announced they were going their "separate ways" late on Sunday night.
They have a son, Bear, who was born in March last year.
Cheryl and I are sad to announce that we are going our separate ways. It's been a tough decision for us to make. We still have so much love for each other as a family. Bear is our world and we ask that you respect his privacy as we navigate our way through this together.— Liam (@LiamPayne) July 1, 2018
Cheryl and Liam first met back in 2008, when Liam was 14 and auditioning on The X Factor.
Liam didn't make it past the judges' houses, but made it into newly formed band One Direction following another audition in 2010.
They got together in 2016 after Cheryl divorced French restaurateur Jean-Bernard Fernandez-Versini.