Hello, I'm Dr. Deb and will do my best to help you today.
I can understand why you'd be so worried about your dog since she/he's so small but there probably wasn't enough chocolate in the cookies to pose a toxicity issue for him/her. But, on the off chance that there was, it's good that you were able to eliminate most of it from her/his stomach.
At this point, I wouldn't feed her/him for several hours since she/he may continue to feel nauseous. She/he may or may not actively vomit again but she/he may still feel nauseous enough that if she/he eats, she/he'll bring it right back up.
Then, when you do offer food, I'd feed a blander diet of boiled chicken and rice, probably for just that next meal or possibly the one after as well.
I wouldn't necessarily expect any looser stools but if they should develop, I'd continue the bland diet until the issue resolves (which should be within another day or so).
I also wouldn't expect any adverse consequences from whatever cookie might remain in her system in terms of significant side effects such as restlessness, pacing, panting, hyperactivity.
I hope this helps to reassure you about her. Deb