Isobel worked as a successful fashion model until meeting Selwyn, who she later married and had a daughter with. She was described as a homebody who rarely traveled to Los Angeles and out of her family's servants, she had a preference for Arkady.
At some point, Isobel was diagnosed with cancer, eventually succumbing to her disease in 2018. As a gift, Eldon Tyrell had a Nexus-7 replicant created for Alexander Selwyn to completely replace his wife. Their daughter, Cleo, was unaware of this, believing that her mother had simply returned from a brief illness.