add family logic

app/Http/Resources/Families/FamilyStudentResource.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace App\Http\Resources\Families;
+
+use Illuminate\Http\Resources\Json\JsonResource;
+
+class FamilyStudentResource extends JsonResource
+{
+    public function toArray($request): array
+    {
+        return [
+            'id' => (int) ($this['id'] ?? 0),
+            'firstname' => (string) ($this['firstname'] ?? ''),
+            'lastname' => (string) ($this['lastname'] ?? ''),
+            'grade' => (string) ($this['grade'] ?? ''),
+        ];
+    }
+}