D.S.
Nut milks have very little nutritional value and don't have enough fat for the developing brain. If goat's milk doesn't work out, coconut milk would be a good choice. Kids less than 2yrs need to get a substantial amount of nutrition from liquids because they can't take in the volume of calories they need to grow from solids alone (due to their small stomach size) - that's why milk is important for them - but it doesn't need to be from a cow or a soybean! It DOES need to have protein and fat - which you get from goat's milk (although it lacks folic acid). I know coconut milk has enough fat, but protein might need to come from solid foods if you use it.
Good luck!
D.