"Chris sought help as soon as she realised there was something not quite right," said Walker.
"She was a doctor and she was very aware of what melanomas are like, but she did not recognise anything on her own body that could have sparked the start of this."
Walsh said her sister - a mother of four and the oldest of five children - was looked up to by the family and had nursed her dying father shortly before being diagnosed with cancer.
"She was the feet in the family, she was the oldest and she was a doctor, she always took charge," Walsh said.
Morgan-Conquer did everything possible to fight the disease and looked at alternative medicine as well as radiation. "She would have a few months of things being good and then one would pop up somewhere else in the body."
Walsh urged people to seek help if they were unsure of any change in their body. "Basically, people need to be very aware. Anything they are unsure of they need to get them checked."
Dr Ric Coleman, a colleague at Millhouse Medical Centre in Howick, agreed and said Morgan-Conquer's death should serve as a warning.
"Her illness was unusual because there was no skin lesion, but in general people should keep an eye on their skin, especially those with any family history of melanoma."
Coleman said Morgan-Conquer was an amazing woman who put other people's needs ahead of her own.
"Chris resonated with the anxious, the stressed and the depressed," Coleman said.
"She listened to their stories, she hugged them and shed tears with them in their sadness and sorrows."
Morgan-Conquer is survived by her husband, real-estate agent James Conquer, and four children, including twins.