If she is having 6-8 really wet diapers a day and is satisfied without any weight loss she is getting enough.
My question is this. Sometimes I can offer just the breast and afterwards she is not hungry. Could it be I am producing enough milk, even though I barely get 2oz when I pump?
So, yes you could very well be producing enough.
Instead of giving her a bottle at night I would just re-offer the breast for more nursing. If she goes for it then I would just keep doing that.