。
She had too much pride to do anything shameful.
Literal
She [topic-は] pride [subject-が] high [because-ので], shameful-thing [contrast-は] didn't-do.
プライドが高い (literally 'pride is high') is the standard phrase for 'has a lot of pride / is proud.' Notice that プライド is a loanword, but in Japanese it carries a more neutral or positive sense than the English 'pride' often does — closer to 'self-respect' or 'sense of dignity' — and so 'プライドが高い' can be a virtue here, not a vice. 恥ずべき is a fixed attributive form built from 恥ず (the classical stem of 恥じる, 'to be ashamed') plus the auxiliary べき ('should, ought to'). Modern Japanese normally attaches べき to the dictionary form (恥じるべき), but a handful of classical compounds like 恥ずべき, 言うべき, and あるべき have survived intact and read as elevated, almost moral language. The contrastive は after 恥ずべきこと sets that category apart: 'shameful things, specifically — those she did not do.'