just to clarify, OP said that toddler finished 3/4 of her drink, not 1/4..
So...
Let's say that DH's "2 teaspoons" was really 1 oz or 2 TB. That would be the equivalent of about 6 oz of wine, divided between 2 smoothies, so 1/2 a glass of wine in OP's smoothie, so toddler drank about 2 1/4 oz of wine, or a little more than a third of a glass of wine. Given that a toddler is likely 1/6 the body weight of an adult, this is pretty serious.
But if DH put in 4 TB, or 2 oz, then toddler is getting equivalent 2/3 of a glass of wine.
and of course, I agree that there are huge issues here. Your husband putting booze in a morning smoothie and not telling you? and not saying anything when toddler drinks it? WHy? BEcause he didn't want to admit that he had put alcohol in your morning drink? the whole thing, including his defensiveness, is so weird, and bizarre.
if you google "toddler drinking alcohol" you will see that a woman in florida was arrested for leaving her 20 month old in reach of wine, the toddler drank 3-4 oz of it and she was arrested for aggravated child abuse.