Django Many-To-Many Create With Intermediary (Through) Table

Models

"""Django M2M With Through Example Models"""

import datetime
from django.db import models

class Child(models.Model):
    """Each Child can have multiple families."""
    name = models.CharField(max_length=120)
    families = models.ManyToManyField('Parent', through='FamilyChild')

class Family(models.Model):
    """Families are groups of children in a particular order."""
    name = models.CharField(max_length=255)
    children = models.ManyToManyField('Child', through='FamilyChild')

class FamilyChild(models.Model):
    """A FamilyChild is the many-to-many intersection of Families and Children"""
    child = models.ForeignKey('Child', related_name='children')
    family = models.ForeignKey('Family', related_name='families')
    order = models.IntegerField(default=0)

am getting a Noreversematch for the url {% url child_create slug=form.family_slug.value %}"

basically i have this child_create under an app

main urls.py
url(r'^samrunbook/', include('samrunbook.urls')),

samrunbook/urls.py

url(r'sam/(?P<slug>[0-9]+)/add/account/$', views.AccountAdd.as_view(), name='account_create'),

So, if I understand correctly, account_create will be e.g sam/8/add/account, but it won't be resolved unless the urls start with

samrunbook/sam/8/add/account

Can you please help how to resolve this issue?.

Hi, I would like to know how are you using the order filed in the through table(FamilyChild).

My question and curiosity is how do we get the list of child in the order mentioned in the FamilyChild model. It would help me understand the extra filed in the model, am new to Django. Expecting something like this.
child1 = Child.create(name='first_child')
child2 = Child.create(name='second_child')
family = Family.create(name='sample_family_name')
family.children.create(child=child1, order=1)
family.children.create(child=child2, order=2)

Now?
family.childrens.order_by(:order) ===> something like. How do we do ? Am from rails background new to django.