Agree! When we attended an admission presentation at U of Washington, the counselor said that most students have a minor blip in grades first semester of junior year because that’s when they are usually taking lots and hard APs. She said they look for improvement.
OP’s daughter improved dramatically. (I’m assuming OP’s child’s transcript will show Semester 1: C; Semester 2: A.) Going from a C to an A in AP Calc is fantastic and demonstrates resilience and excellence in a rigorous class.