The importance of the SAT/ACT score depends on the schools your DD is interested in.....Ivy League schools are going to place more emphasis on test scores than most. My suggestion would be to have your DD take the test. If she scores well you publish the score with pride. If she doesn't score well, you do not publish it, and if asked she can simply reply that she plans to take it as a junior.
Just be sure to keep in mind that many schools want ALL of your scores, not just your favorites. I think maybe the OP is worried that the sophomore year scores specifically will be low? Low sophomore scores aren't the end of the world - the colleges will look at the junior year scores and improvement will be taken into consideration.
I just want to underscore that a highly motivated student will do well ANYWHERE.