What a sweet baby! $10 in for Belle!
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.