Ask a Dog Vet and Get Answers to Your Dog Veterinary Questions
As long as it is milk chocolate then there is likely not enough to be a problem for your dog at her weight. You may expect some GI upset however as she is not used to eating things like that and it may cause some GI irritation.
Monitor her for hyperactivity, restlessness, vomiting, diarrhea or lethargy. If she experiences any of these, she needs to be examined right away to determine if she is having side effects from the chocolate.
If she experiences GI upset, you can feed a bland diet as follows:
a lean protein source (boiled skinless chicken breast, low fat turkey breast boiled low fat hamburger, or low fat collage cheese) and rice or plain pasta (no butter or salt!!! that will make her feel worse). Feed this in a 1:2 ratio of protein to carbohydrate and start with a few table spoons every few hours, then work up to a normal meal at her normal feeding times if she tolerates this without vomiting. Withhold food for 4-6 hours before offering her anything and offer water first. If she does ok with this, then you can offer her food.
Does this help to address your concerns tonight?