I have a somewhat defiant dog too -- it comes with the field breeding. They have to have that hard-headed streak in order to persist through flooded timber and ice-covered ponds after that wounded duck . . . .
Lots of heeling work and plenty of long walks will keep her tired, which will make her more compliant. If she likes to retrieve, join a retrieving club and get her a job, that will give her something to do and she'll realize that she gets to do it because of YOU. Also try clicker training, I've found that very helpful with Ruby. And just having a consult with a pro, maybe one that specializes in field Labs, may help.
Thanks for the info. I think I will be trying one of those things because she has been unbelievably sneaky and defiant. Very smart because I’ve already taught her 7 tricks. I trained her from day one to stay off the carpets and she’s been very obedient about that but everything else.....not at all. I had a Siberian husky and Springer Spaniel before that died of old age and they were so easy to train. I’ve never really stopped grieving over losing them and swore I’d never get another dog but the kids wore me down.