OP here - just wanted to provide a quick update to all, My D did talk to her advisor and she is now thinking it might be doable. She has drafted a schedule that would allow her to study abroad spring of her junior year and still graduate in 4 years, but it requires her taking some classes out of sequence (like Physics 2 before Physics 1) and taking a Chem class while abroad but not taking the corresponding lab until she returns to her home school. So it looks doable, but not necessarily easy. She seems pretty motivated at this point, so we will see. Thanks to all for your feedback!