Like i said if she had of asked i would never of said no they are not invited, but because she hasn't asked and is just bringing them along i find that rude!
I understand that you're feeling it was a rude assumption to make, but if you weren't going to tell her no if she asked anyway then isnt it all a moot point at the end of the day?

I guess it all depends on what your friendship is like and where you want it to go as to where to go from here. Honestly I think it was just an honest misunderstanding on her behalf, as you can see from 80% of the responses from this thread that would have taken the same invite the same way?