The common odors associated with diabetes are acetone (pear drops breath) and vinegar (acetic acid) which are the excess waste products from burning ketones instead of glucose. These are often also associated with a severe condition known as diabetic ketoacidosis (DKA) which can happen if diabetes is not under control. If you are doing a strict low-calorie or low carb diet, then it may just be keto breath which is a natural consequence of those diets, and nothing to be concerned about.
However, garlic sweat would probably be due to another cause. Some people recovering from Covid-19 report strange smells, so it may be necessary to get your bestie to do an independent check to make sure it is not your olfactory system playing up.
Do you have access to a glucometer to check your sugar levels when this is happening?