he 35-year-old mother was attacked on Saturday afternoon.

The woman who was attacked by a great white shark at Sydney’s Coogee Beach will lose her arm as she fights for life in hospital.

Leah Stewart, 35, was swimming with two friends within the flagged area when she was attacked on Saturday morning.

She suffered critical injuries, including multiple bites to her arms and legs, lacerations and fractures throughout her body, her family said.

She is still fighting for life in hospital after suffering significant blood loss.

7NEWS understands Stewart’s partner was in Canada’s Vancouver for the World Cup at the time of the attack and has since departed for Australia after being informed of what happened.

Her family said they were “shocked and devastated” that the attack happened to a “beloved partner, daughter and mother who is so full of life and energy”.

“Leah is a dedicated and loving mother, a passionate teacher, and a Coogee local who loves the ocean,” the family wrote on a GoFundMe page.

They said Stewart required the amputation of one arm and has undergone several other surgeries.

“Leah remains in a critical condition on life support and has undergone multiple surgeries in the days after the attack,” they said.

“Leah faces a long road to recovery and your support will make a huge difference in her quality of life, rehabilitation and ability to go back to being a mum to her much loved one year old daughter.

The family also expressed gratitude to first responders and medical staff involved in Stewart’s rescue and treatment.

“Our sincere thanks to the lifesavers, first responders, helicopter crew, and to the dedicated medical team at St Vincents who have been caring for Leah and our thanks to all who have reached out to the family with sympathy, care and prayer,” the page reads.

“Any contribution, no matter the size will be deeply appreciated as it will help support Leah, her partner and daughter through this heartbreaking situation.”

Locals told 7NEWS.com.au the young mother was swimming about 30m offshore near the centre of the beach when she was attacked.

A witness said there was a large amount of blood in the water following the attack.

Surf lifesaver Charlie Verco, 24, raced towards danger to help save Stewart as the shark continued circling in the bloody water.

“I’d like to think I did enough to get her in fast enough,” he told 7NEWS.

“Once I had her next to me, I was just going, ‘keep your head above water, keep breathing, you’re doing really well, we’re almost at the beach.’

“Just anything, I guess, to feel the silence. It wasn’t conversational. She was not in a great way.”

Footage showed Stewart clinging to life on the hero’s paddle board while a shark alarm blares in the background as he brought her back to shore.

On the beach was an off-duty critical care doctor, paramedics and lifeguards who were waiting to save the woman who was then rushed to St Vincent’s Hospital.

Beaches in Sydney’s eastern suburbs reopened on Monday, with drones deployed overhead as authorities stepped up shark surveillance.

Randwick City Council said jet ski patrols were also underway to monitor for sharks.

The Civil Aviation Safety Authority has granted a temporary exemption allowing aerial surveillance over Coogee Beach, about 8km from Sydney Airport.