My DH's cousin doesn't discipline at all. His younger 7 year old is a real spit fire too. He will yell at her to stop or to do what she is told but doesn't follow through. He tells my husband "you'll see". Our son is 3 and we still haven't seen yet and we never will see.
I get so sick of people wanting to be there child's best friend. You are there parent not there friend. You can love them and have fun with them but you are not there friend.
The Rabi on TLC said it best. When you don't discipline your child you are not loving your child. You are setting them up to fail.
Just my two cents.
Jen...

Nice to see that celebrity moms can be lousy parents, too. Just read an article about Leah Remini (from the King of Queens); she and her hubby are absolutely RULED by their 3 year old who is still in diapers and still drinks from a bottle and sleeps in their bed Her husband says they haven't had "relations" in their own bed since the little br....darling was born!!!! Because they want to be friends with their child, she gets away with anything! My nieces are the same way; undisciplined and no table manners. My husband refuses to attend family dinners anymore because my 10 year old niece will eat soup with her hands and the 13 year old will drink from the bowl and their mother gets VERY upset when anyone tries to correct their behavior. And it's not fair to my kids who actually have manners (most of the time ) and get disciplined to see these girls do whatever they want with no consequences

Tell your kids there will be consequences to those other ones - no one will want to be around them - and doesn't everyone want to be surrounded by people who want them there?