The Apartment  a Novel by Danielle Steel.  Claire Kelly, Abby Williams, and five years later, Morgan Shelby, Sasha Hartman, join them and became sister’s in an apartment loft in Hell’s Kitchen.  Claire is a shoe designer, Abby is a writer, Morgan is in finance, Sasha is a Doctor and Valentina is a headliner supermodel and drops by to see her identical twin, Sasha.