I think having that many children is irresponsible. When it comes to the point that your children are raising your children--that is neglectful in my opinion. Sure the kids look happy, they may even say they're happy. But what life have these kids even lived excpet for raising their siblings?
Where does this mother find the time to nurture her children? Where do they find the time to spend quality time with each child, as each child requires? They don't. They have their older children do this for them? I don't think that is fair to the children at all. They should be able to grow as individuals and learn who they are instead of trying to raise their younger siblings. But that's just my opinion.