Looking at it from a different angle, your supervisor is a newish member of staff and you are her first PhD student. She was probably really pleased to get the chance and was near enough to her own PhD to try and be the dream supervisor - friendly, always supportive, getting you involved in other projects etc. Then came your viva and her senior colleagues make it very clear that they think there are some real flaws in your project. Now you are understably upset with the criticism but I bet she's been taken to task too and been told that she's not doing you any favours by not making sure your work is up to standard to pass the PhD. She's now trying to take that advice on board and work with you accordingly. This is awkward for both of you and from what you say neither of you is managing it well right now.

Definitely you don't owe anyone anything. It would be courteous to tell your supervisor that that's your intended path though as they then know where they stand. Like anyone who's worked outside academia before doing a PhD, I have to warn you that there are MUCH worse places for back-biting etc though so don't be surprised. I have a friend in banking and his tales make my hair stand on end and no it's not about big deals etc, it's the petty small things just like every job I've ever had.