Listening to AB talk you learn a lot about the development of syntax. The other day CJ found her mitten strap, which had gotten wedged into a crevasse in her carseat. “CJ saved the day!” I said. AB, who likes to repeat things, said
“CJ saved a lot of day!”
So she knows that “a lot of” is a sort of intensifier but is still learning when and where it can be inserted.