title: How to use a variable in v-model or :value
body: <p>I am using v-model within a component and I want to dynamically update the v-model to point to an object.</p>
  
  <p>I have a component which is a form and I want to use v-model or :value to prefill the inputs.</p>
  
  <p>I am inserting the data via a prop and I am getting the <code>childId</code> from a click event and then using the info to populate them like so. ie: <code>&lt;input type="text" class="form-control" id="child_name" v-model="children.child1.name"&gt;</code></p>
  
  <p>I need to change <code>child_1</code> to a variable so it could be child_1 or 2 or 3 or 4. I've tried replacing it with a string variable which breaks to flow. Any ideas how to solve this issue? I've often used variables in Vue before but never for v-model or value.</p>
  
  <p>I am using this sample data:</p>
  
  <pre><code>childId: child_1
  
    children: {
        child_1: {
          id: 'child_1',
          name: 'Ruth Ann Morgan',
          gender: 'female',
          birth_year: '1999',
          parentage: 'our_child',
          dependency: 'not_dependent'
        },
        child_2: {
          id: 'child_2',
          name: 'James Nico Morgan',
          gender: 'male',
          birth_year: '2012',
          parentage: 'our_child',
          dependency: 'is_dependent'
        }
    },
  </code></pre>