Your ECs are going to tell adcoms two different stories, a humanities one and a stem one, which I don’t think you want, unless you can combine them (e.g. how humanities or ethics can affect pharmaceutical industry). So you may want to pick a major form chem or art history and talk about the other. In the schools you listed, they’re both in thill be e same school - arts and sciences, so the admission standards will be similar. Chemistry could be an advantage for a female stem applicant.