SwiftUI Core Data Relationship Not Updating View

struct ContentView: View {
    
    @Environment(\.managedObjectContext) private var viewContext
    
    @FetchRequest(sortDescriptors: [SortDescriptor(\.name)])
    private var parents: FetchedResults<Parent>
    
    @State private var editingParent: Parent?
    
    var body: some View {
        
        List {
            ForEach(parents) { parent in
                VStack(alignment: .leading) {
                    Text(parent.name ?? "No Name")
                    Text("\(parent.children!.count) children")
                    Text("\(getNumberOfStar(parent: parent)) Stared")
                }
                .onTapGesture {
                    editingParent = parent
                }
                                
            }
        }
        
        .sheet(item: $editingParent) { parent in
            ChildrenView(parent: parent)
        }
        
        Button {
            PersistenceController.shared.saveParent(name: "New Parent")
        } label: {
            Text("Add Parent")
        }.padding()
 
        Button {
            parents.forEach { parent in
                PersistenceController.shared.delete(parent: parent)
            }
        } label: {
            Text("Delete All")
        }.padding()
        
    }
    
    //this function does not get called when the database changes
    func getNumberOfStar(parent: Parent) -> Int {
        let children = parent.children!.allObjects as! [Child]
        let starred = children.filter({$0.star == true})
        return starred.count
    }
    
    
}

    
    
    @FetchRequest var children: FetchedResults<Child>
    
    var parent: Parent
    
    init(parent: Parent) {
        self.parent = parent
        _children = FetchRequest<Child>(sortDescriptors: [], predicate: NSPredicate(format: "parent = %@", parent))
    }
    
    
    var body: some View {
        List {
            ForEach(children) { child in
                HStack {
                    Text(child.name ?? "No Name")
                    Text(child.star ? "⭐️" : "")
                    Spacer()
                    Button {
                        PersistenceController.shared.updateStar(child: child)
                    } label: {
                        Text("Toggle Star")
                    }
                }
            }
        }
        Button {
            PersistenceController.shared.saveChild(name: "New Child", parent: parent)
        } label: {
            Text("Add Child")
        }
    }
    
    
    
}
 

    
    static let shared = PersistenceController()
    
    let container: NSPersistentContainer
    
    init(inMemory: Bool = false) {
        container = NSPersistentContainer(name: "Model")
        if inMemory {
            container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
        }
        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
            if let error = error as NSError? {
                // Replace this implementation with code to handle the error appropriately.
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
                
                /*
                 Typical reasons for an error here include:
                 * The parent directory does not exist, cannot be created, or disallows writing.
                 * The persistent store is not accessible, due to permissions or data protection when the device is locked.
                 * The device is out of space.
                 * The store could not be migrated to the current model version.
                 Check the error message to determine what the actual problem was.
                 */
                fatalError("Unresolved error \(error), \(error.userInfo)")
            }
        })
        container.viewContext.automaticallyMergesChangesFromParent = true
    }
    
    func save() {
        let viewContext = container.viewContext
        do {
            try viewContext.save()
        } catch {
            /**
             Real-world apps should consider better handling the error in a way that fits their UI.
             */
            let nsError = error as NSError
            fatalError("Failed to save Core Data changes: \(nsError), \(nsError.userInfo)")
        }
                
    }
    
    
    func saveParent(name: String) {
        let newParent = Parent(context: container.viewContext)
        newParent.name = name
        save()
    }
    
    func saveChild(name: String, parent: Parent) {
        let newChild = Child(context: container.viewContext)
        newChild.name = name
        newChild.parent = parent
        newChild.star = false 
        save()
    }
    
    func updateStar(child: Child) {
        child.star.toggle()
        save()
    }
    
    func delete(parent: Parent) {
        let viewContext = container.viewContext
        viewContext.delete(parent)
        save()
    }
    
    
}

struct Core_Data_Child_Save_ExampleApp: App {
    
    let persistenceController = PersistenceController.shared
 
    
    var body: some Scene {
        WindowGroup {
            ContentView()
                .environment(\.managedObjectContext, persistenceController.container.viewContext)
 
        }
    }
}