Because she had grown romantic, she had not yet fallen into the kind of passive frame of mind that accepts the idea that, wherever a person is, they should find some little corner to live in and arrange their whole life around it.
Literal
[topic-は] romantic [adverbial-に] had-become [because-ので], humans [topic-は] wherever-it-may-be somewhere corner [in-に] should-live place [object-を] find, its surroundings [in-に] own whole-life [object-を] arrange-go should [explanatory-だ] [quotative-と] [nominalizer-いう][nominalizer-こと-を] accept [simile-ような] passive mental-state [in-に] still had-not-fallen [explanatory-のである].
A long, layered sentence in distinctly literary register. Several features stand out. どこであれ is a literary 'wherever it may be,' built from the であれ pattern (the imperative of である, classical for 'whether one is X or not'). Twin ~べき modals stack: 住むべきところ ('a place where one should live') and 整えていくべき ('should go on arranging'); ~べき expresses moral or expected obligation — what 'ought' to be. The phrase ~ということを受け入れる ('accept the proposition that...') uses ということ to nominalize a whole proposition into a graspable object. ~ような ('the kind of...') turns the verb 受け入れる into a noun-modifying clause attached to 精神状態. The clause-final のである is a formal explanatory copula common in essayistic and philosophical prose — a more weighty cousin of casual ~んだ. The whole sentence reflects on the romantic spirit's resistance to settling for a small, conventional life, a theme typical of late 19th- and early 20th-century European fiction translated into Japanese.