How many feeds does her 1.5 litres split into ?
Mine were slowly brought down from 4 to 1 over weeks. Gradual, yo got to be able to see her drink water in my book before you drop one, or if her grazing increases, drop one then maybe. Mine have they're water changed a few times a day, I never think oh hey haven't drunk it, they're not thirsty, I change it anyway, they can be very very fussy lol.