Ozzy and Sharon Osbourne's eldest daughter Aimee has had surgery after a breast cancer scare.
Sharon Osbourne said Aimee's operation "went very well"
Aimee, 21, who did not appear in the family's TV show, had a lump removed from her breast, her mother said.
Sharon said her daughter was still being treated after "minor complications" but added: "We're sure she'll make a complete recovery."
The pair recently pulled out of a six-week run of stage show The Vagina Monologues so Aimee could be treated.
Sharon's statement said: "Aimee's had a breast cancer scare. She found a lump on her breast which she's had removed.
"The operation went very well on the whole but there have been a few minor complications and she will be having more treatment and lots of rest over the next few weeks.
"We're sure she'll make a complete recovery. Thanks so much for all of your support - you've all been fabulous.
"Health really is the most important thing in life. After the 12 months we've had, no-one realises that more than me. I promise to let you know the second that she gets the all clear."
The news comes after the family's Buckinghamshire home was burgled then caught fire and, in December 2003, Ozzy almost died in a quad bike accident in the grounds.
Sharon was diagnosed with colon cancer in 2002 but made a full recovery.
Aimee reportedly did not want to take part in the family's hit fly-on-the-wall show The Osbournes because she wanted to launch a music career without relying on her parents' fame.