Not soy milk.
It has naturally occurring estrogen in it, which is said to affect the adrenal glands/hormones in children, and being the adrenal glands are still developing in a child, it is affected by it.
Long story short: a friend has twin girls. At about 6-7 years old, they started to menstruate. My friend gave them soy milk due to preference, and her girls LOVE soy milk and drank it readily. The Specialist they saw, per the abnormally early menstruation and much research into their family said, stop... giving them the soy milk. It took several months, for their bodies to regulate and normalize, for the menstruating to stop.
For toddlers, the reason whole milk is recommended is that the "milk fats" in it is an essential nutrient for brain growth and development.
That said, try asking your Pediatrician, what alternatives there are.
Whether or not you use cow's milk, is a personal choice.
There is also organic whole milk.
Then, there is the factor about WILL the child like it, and/or any other milk alternatives you try. Some toddlers like it, some do not.
My son, from breastfeeding, just switched to whole milk (cow's), very easily. My daughter on the other hand does not like milk of any kind. So then, she has to take calcium supplements. Girls, especially, need the calcium as well.
My sibling is lactose intolerant. I am not.
Each person is different. But we are in the same family.
And, none of my parents are lactose intolerant.