In medicine My child has to have 1 ml If I use a teaspoon to give it to her how full does the spoon have to be?

A teaspoon holds 'about' 5 ml, so the spoon would need to be 1/5 full - but, for such a small amount of medicine it would be safer to use a pippette (dropper) where you would be able to measure 1 ml more accurately.