It would have been better if she'd said, "we're simply being affectionate like any couple." Although, I concur, it does depend on how you read that. (Aside: I think your interpretation is not the one intended - but still.)
As far as family members kissing, No, that would not be deviant behavior since normally family members kiss. Same would hold true in other cultures where it is quite common for same sex kissing. It is normal in those cultures.