My D has a perfect ACT score with a low writing score, and her subsection scores are all 36 except for math. On the other hand, her SAT score is 1540 (740 R/W, 800 M) with 23/24 in essay. Since the weakness of math and writing on ACT is compensated by the strength in SAT, should she send both scores or just the ACT?
While I’m sure your DD appreciates your help and interest, we are not applying to college - she is.
If I were her, I would send both, both of which are excellent. It won’t hurt, and may help. Good luck to her.