。
She always insists on having things her own way.
Literal
She [topic-は] no-matter-what self [genitive-の] [as-one-wishes-思い通り] [adverbial-に] do [tries to-ようとする].
思い通り (omoidori) literally 'as the mind goes,' meaning 'just as one wishes / one's own way.' Pairs naturally with adverbializing に and the verb する ('do, make') to form the standard idiom 思い通りにする ('have one's way / make things go as planned'). The frame [volitional]+とする here means 'try to' in its positive sense — the negated mirror ようとしない would mean 'refuse to.' Paired with どうしても in a positive predicate, it becomes 'no matter what, she tries to...' — pure willfulness.