1/3 tsp equal to ??

my three year od got pills from the dr's yesterday and i am to give her a 1/3 tsp of this prescription...trouble is the medicine spoon does hold a mark for that and i cant find any that do within my house and i have a ton.more or less how many mL's is this or between what grades should i be looking at?? HELP A teaspoon is 5ml. 1/3 of a teaspoon 1.67 ml, or just underneath 2 ml.
The standard Tylenol for infants/toddlers dropper should have markings of 0.8 and 1.8 ml on it.
DO NOT eyeball it. Volume length can be deceptive. Eyeballing it is fine for baking cookies, but this dosage is for a small child. Small differences business.
If you're really stuck, call your doctor and ask if it would be better to use a standard 1/4 or a 1/2 teaspoon measure spoon. (1/3 is in the middle of these two, and not a standard measure spoon size.)
Your doctor will know where your child fits on the weight/dosage chart, and whether to round up (to 1/2) or down (to 1/4).
eyeball it contained by a teaspoon