She multiplied the 2 on the outside of the parenthetical by each of the digits on the inside, ie 2(1+2) = 21+22=2+4

That was the wrong order of operations, but that's how she got there.

Edit: Or maybe it isn't the wrong order of operations, going by what some other commenters are saying. I like the notion that this is a language problem, not a math problem.

She multiplied the 2 on the outside of the parenthetical by each of the digits on the inside, ie 2(1+2) = 21+22=2+4

That was the wrong order of operations, bu that's how she got there.