My mother insists that we be home by seven in the evening.

Literal

Mother [topic-は] no-matter-what us [subject-が] evening seven [by-までには] home [to-に] return [indirect-command-ようにと] is-saying

どうしても = 'no matter what / at all costs.' までには = 'by (the time of)' — まで (until) + に (at) + は (emphasis). ~ようにと言っている = ongoing insistence.